Welcome to the Community Forum and thanks for your post. It's really great to see new faces on the Forum. I'm sorry to hear that you've been having problems registering your tablet via the TV Anywhere app and apologies for the delay in getting back to you.
I have been able to access your account via your Forum details and can see that you called in and spoke with our Technical Support Department about this and you were able to get a device registered, but this wasn't your tablet.
If you have already tried uninstalling and reinstalling the TV Anywhere app on the tablet and you are still getting the same issue, it's possible that the tablet is not compatible. Here's a link showing supported devices: Supported Android Devices for TV Anywhere