A family of Microsoft word processing software products for creating web, email, and print documents.
This is a hardy perennial that seems to be somewhat sporadic. I truly don't know what causes it but it's usually easier to use Table> Select> Table. There's also a built-in keyboard shortcut [Option+Clear] if your keyboard has an available Clear Key (It's normally contained in the top row of a numeric keypad on full keyboards.):-) If not, you can assign a custom keystroke to the TableSelectTable command.