If you try to swallow too much food at one time, you might choke.
He swallowed a mouse.
The word "swallow" is also found in some expressions. In this case, if you "swallow" something, you believe it to be true. The word "swallow" is also used when reading or listening to information.
I find that very hard to swallow. (I don’t think that’s true.)
This is too much information to swallow at one time.