Questions about example sentences with, and the definition and usage of "Gochisousama"

A: In American culture, we don't really have the custom of saying something before and after eating.

Some religious people will say a prayer before eating, that act is called "saying grace"

I think the simplest way to translate gochisousama would be "thank you for the meal", but you would only really say that if you were at someone's house and they cooked for you.