I agree with Craig; if it's a solid plastic container with a snap seal like Tupperware, we would just call it "a container." Tupperware is a brand name and, unlike some others, it has not become a generic word. If it's dry "finger food" like a sandwich, or crackers, or cookies, and we just want something to keep it clean (and to keep whatever we put it in clean), then we would use the word "baggie" (for a thin, flexible plastic bag with a snap seal).

You could say "put it in a tupperware" and that is perfectly acceptable. You could also say "plastic container," or simply, "container" and everyone will know what you mean if you are speaking in the context of leftovers.

In Colombia we say "coca" for a plastic container. Strange , right?

Are you that Tupperware translates as 'coca?'