These worms are specially sold for the purpose of vermicomposting. They are extremely cheap, and people with their own vermicomposters will often just give you a whole bag full, because, as you could've guessed, these worms multiply. A large container of some sort that's not made of metal will suit them fine. Big Rubbermaid brand containers work well, especially because there needs to be holes in the lid of every worm's home. Think width, not depth when looking for your container.
Worms prefer to spread out a bit while they dine.
Give them some room to move. Acquire a large, plastic bin. Either a Rubbermaid container or a pre-made vermicomposting bin.