cant seem to install windows phone games on windows tablet
Yeah... about that. You don't mention the make/model of tablet, but if it's fairly new, it's probably running Windows 8.1, not Windows Phone operating system. While Microsoft is working on making all devices - computers, tablets, phones - run on a single operating system, with a single apps store for both computers and phones, that is not the situation right now.
You have the advantage of being able to run the apps in the Windows store, but the disadvantage of not being able to run apps that are in the Windows Phone store.