Originally Posted by BeeTee-Ess
No, I am talking about Calibre's own Tag Editor button, the one beside the Tags: box on the Edit Metadata dialogue. I expected it to offer me a choice based upon the 60 or so which come with the Goodreads plugin.
The tag editor isn't tied to any metadata plugin. The tag editor show you the existing tags for all of the books in your library. This means you have tags that weren't placed in your library by the goodreads plugin.