The redistributables are used to provide support for apps that have been developed on Visual C platform, and those apps use shared libraries and code. Many developers include these libraries in their setup packages, but given the fact that almost all users have these libraries on their PC, it's easier to just release the product without them. Sometimes you don't even have to worry about them. If they're installed on your PC, the app will work just fine.
As always, if you remove them, note their name in case something goes wrong and have to install them back.