DLC Files

New here. Do I need to keep DLC files (in my game folder) after installing them, or can I  delete them?  Thanks.

That's a weird question that doesn't make much sense as is.
DLC content inside your game can't be removed if you want to use it.
Perhaps you meant the package files themselves? But even if you did, those shouldn't go inside the game folder either way, those are just installers.