Seeing as my comment is getting popular, I may as well give people the chance to vote on it.
I would recommend deleting the tab-key and tab tags. tabs makes sense, and we could make tab a synonym for it. Tabs are a useful GUI feature and I can imagine interesting questions that revolve around them.
The tab and tab-key tags seem useless to me. Why would we want a tag for a particular key on the keyboard? Granted it is one used extensively by those of us who regularly use SHELLshell autocompletion, but what kind of computer problem, that can be expressed as a question and answered on this site, would be tagged as tab?
I suggest synonymizing (what a horrible word) tab and tabs and nuking tab-key.