the tablet part makes no sense, you can always create new Google account or just use tablet without google account, installing apps through aurora store or apkmirror would be minor annoyance though
After you sign into an Android device with a Google account then factory reset it, you have to sign in with the same account before you can use a new account. It's an anti theft precaution.
AIUI that's only if you "factory reset" from outside the installed OS. You can explicitly remove the existing account from your device, and I think the OS-level "factory reset" function actually does this for you.
you can almost always bypass FRP, need more information on tablet model and Android version
What we really need is the ability to "release" it from the old account. Imagine selling a device and the new owner demanding your password...
Sorry if you don't believe it, but I tell the truth here. No need to make things up. The tablet required one to have a Google account connected in order to use it, plain and simple.