A 100k food box is an item in Evony TKR (The King's Return).
The description of 100K Food Box in Evony TKR says:
Use it to gain 100,000 Food.
100K Food Box is known to potentially be obtainable from opening Junior Spring Festival Rewards, Lv11 Boss Monster Chest, Lucky Box Ⅲ, Lucky Box Ⅴ, Lucky Box Ⅶ, Lv12 Boss Monster Chest, Medium Lava Turtle Chest, Senior Lava Turtle Chest, Medium Golem Chest, Senior Golem Chest, Medium Witch Chest, Medium Warlord Chest, Lv14 Boss Monster Chest, Junior Hydra Chest, Medium Hydra Chest, Legendary Lava Turtle Chest, Legendary Golem Chest, Legendary Witch Chest, Legendary Warlord Chest, Epic Golem Chest, Epic Witch Chest, Uncommon Ymir Chest, Super Ymir Chest and Legendary Ymir Chest. The links for each item are below:
Note: This list may be incomplete.