As long as you didn't buy "treated" mealworms (the ones dusted with vitamins for birds or lizards,) you've officially got yourself a mealworm farm! There are good ideas on how to set one up in pretty much any sort of space, right here on BYC. I've used a terrarium (pretty, but hard to maintain without mildew,) several different types of plastic containers and a two-gallon aquarium with a few inches of dry oats and the bottom portion of an egg carton.
The egg carton aquarium worked best, but my favorite was a big, cracked bowl that I didn't want to throw out but could no longer use for its intended purpose. I kept it out on my kitchen counter, where it was pretty much ignored by everyone until my mother visited. I wish I'd had a camera on her reaction ... it was priceless!