When tagging manually I didn't notice that there is an option to automatically tag the rest of the songs, if one is populated by Album and Artist. It would be nice to have that option for albums that are not compilations, since all songs have the same artist and album name, right?
One general way of achieving this might be to support copy/paste for multiple lines/columns. This is the way it's done in some other tools. It depends on the support for the approach within the table component we use (SlickGrid atm).