What will happen when I remove my Google account from an Android tablet?
1)  Correct.  You are simply removing your Google account from the tablet, not completely deleting your Google account permanently.

2)  Yes and no.  Yes in the fact you will not be able to access information via apps like Google Drive or Gmail any longer, but if you downloaded any files from them for viewing offline (music, photos, documents, etc), those will still remain on the tablet.  You would either have to delete these items individually, or performing a factory reset of the device (which will remove everything), taking it to the state of where it was brand new out-of-the-box.