It is even more outrageous. I believe it's different every time. Right now, the one I have asks for 30 tomatoes, 9 of the fried fish with lemon, 30+ carrots, 13 of the whipped cream things, and a few other things i can't see yet because i completed them. I believe they were something like ~12 apple pies, ~10-15 baked potatoes, ~8 meat hooks, about ~30 potatoes, and something else... possibly corn or potatoes or something.
Reward is 5 gems, 160 xp, and 260 gold. Once delivered, it takes 12 hours before you can get the next delivery.
You have a time limit to get all of the items loaded onto the train which, for me, was over a day (I can't remember). You cannot 'discard' the requirements for new requirements like you can with the deliveries. Once any of the items you get are loaded, you cannot get them back.