A general rule for these tables: There's a 10% chance of a monster attack, 10% chance of traps, 10% chance of terrain difficulties, 10% chance of flavour, and 10% chance of weird shit. Roughly.
The forest is as dangerous as the Taiga, but all it's threats are hidden and beautiful. Idyllic, but don't eat the mushrooms.
1-2: 2D10 tiny glowing fairies slowly circle party in ring, singing. Paralyse on touch, then cut out heart and enter cavity.
3-4: 3D6 Bush Babies. AC 10, HP d4. Paralyse on touch, then climb up adventurer to eat. Vulnerable to caring words.
5-6: 2d10 Mushroom men shoot poison darts from the trees. They will use guerilla warfare, shooting and then vanishing into the trees, laughing. Roll 1d10 for each dart. (1) trip out, (2) suffer a horrible slow rotting disease that will make you lose a leg, (3) Massive swelling around affected area, (4) Massive rainbow boils swell to burst with hallucinogenic gas, (5) Blood won't clot, even smallest wounds will continue to bleed until death, (6) Sweaty areas sprout with corrupting fungus, (7) Paralysis, one limb at a time, over a period of days, (8) Mind rots away, lose memories and points of int, (9) Extremities curl and turn black, (10) Extremities - fingers, toes, etc - split off you to become Mushroom men. All effects will take a day or two.
7-8: Great shambling mossy tree-beast in the mist. Anyone it turns it's gaze on begins to sprout flowers, turning into a plant. Make it gross and debilitating - eyes burst and bloom into orchids, legs root into ground, mouth chokes on blossoming fruit.
9-10: Princess Mononoke. Masked girl with poison dagger, two massive white wolves, painted with red markings. Will stealth and stalk the party until their guard is down, then race in and strike.
11-12: 2D6 Butterflies flutter from trees - some brown, some multicoloured with eye markings. Land on people and suck up their life-force, gaining colour. Those with full colour can use it to emit a blinding flash attack.
13-14: Wind chimes hang from trees. Tiny wires strung everywhere will set them ringing when crossed. Shaman above will summon Dagger-storm if he hears the chimes ring; makes knives fall as rain in a mile radius.
15-16: Stream flows over mossy rocks. Moss covers all of ground for miles. Many patches of moss are just thin camouflage stretched over the mouths of the moss-beast.
17-18: Mushroom village visible through trees.Mushroom-men have laced the surrounding ground with tiny poison spikes.
19-20: Thin, trailing vines hang from trees like curtains. Will latch onto adventurers with tiny mouths and begin to suck out blood, excreting poison that leaves them slow and lethargic.
21-22: Heavy leaf-litter conceals poisonous snakes.
23-24: Edible mushrooms. Roll 1d5: (1) Hallucinogenic, (2) make you grow to gigantic size temporarily, (3) shrink to tiny size, (4) poison, (5) revelatory dreams, (6) go blind.
25-28: Lumberjack camp - tons of tools for sale.
29-30: A massive white stag. Will help the pure of heart. Kill it, and a massive black horror-ooze will emerge from it's corpse.
31-32: Fairy ring of mushrooms, portal to fae realm.
33-34: Hollow tree with tiny family living inside
35-36: Troll village, friendly.
37-38: Forest floor covered with leaf-litter; uncovering it reveals that you're walking on massive piles of Leprechaun gold, will all vanish three days after being taken.
39-40: Travelling freak show. Will give party food and rest for coin, but disappear at inconvenient time.
41-44: Woods whisper faint phrases.
45-48: Flower fields, with big bee hives hanging from the trees around. Bees buzzing around pollinating.
49-50: Close trees - carts and cars have trouble. Dark even at mid-day.
51-54: Mist and rain. The trees start to shiver, spraying raindrops everywhere.
55-58: Warm day. Snowflakes fall. Some of them are in the shape of pictures, and some of those foretell future events.
59-62: Forest fire.
63-64: Trees part to reveal clearing around lake choked with lilly-pads. Small island in centre.
65-66: Ancient, beautiful ruins. Statue of lovers in centre surrounded by rare roses. Passage underneath leads to hidden underground bathing pool.
67-70: Babbling brook in path, must ford or go around.
71-72: Massive amounts of birds congregate here, all different varieties.
73-74: Woodwives having a picnic. Have only a front - hollow rot behind. Can cure or cause diseases.
75-76: Cliff in path.Steep and overgrown.
77-78: Ground takes sudden, steep turn downwards. Slippery with leaf litter and treacherous with tree roots.
79-80:1D3 Maggot Naga twined around tree - beautiful blind women with giant maggots for legs. Ask the party riddles. Correct answers rewarded with good luck.
81-82: Thin black shadow-men stalk party, feed from their dreams. PC's will lose memories - spells, weapon training, etc - as shadow-men grow fat.
83-84: Noblemen follow the party stealthily. Devour any corpses they leave behind, gaining the powers of each.
85-86: Glisters follow along with party; bright will-o'-the-wisps that feed off emotions. Change colour depending on emotion PC's display, emotions in their presence are heightened to the point of insane outbursts. Gather to strong emotions.
87-88: Tree with bulbous purple fruit. Closer inspection reveals that the fruit is skeletal human heads. Eating will give you +1 intelligence, but give you a split personality.
89-90: Wide river. Those who travel down it will see ghostly cities of incredible beauty appear on the shore at night. Men and women with glowing eyes will stop and beckon to the travellers. Anyone who lands on shore will never be seen again, obviously.
91-92: Wedding between a Hollow Bride and a giant wolf, with fairies presiding as priests and revellers. PC's invited to attend.
93-94: Three riders pass the party: one Day, one Twilight, one Midnight.
95-96: Beautiful glowing part of woods in eternal twilight. Idyllic; full of edible food and water. Party will begin to lose memories and minds the more they stay. Days will secretly pass in hours.
97-98: Maiden sits on lilly throne in pond surrounded by weeping willows. Storks everywhere, spike-things come from her elbows and knees. Takes a liking to PC, offers to take him down into pond with her. If they accept, she will give them a stork afterwards - the stork will die instead of them if they reach 0 HP. They will not remember what happened down there.
99-100: The Wild Hunt charges through and captures the PC's. They will be hunted for the pleasure of the Fairy King.