It goes like this. You're scanning the sections at top of the site and you see all the usual tabs like News, Reviews, Cheats, Walkthroughs... and then there's "Babes." Really?, you say to yourself as you shake your head.
"Babes tab" refers literally to that tab at the top of an otherwise unrelated website; it also refers metaphorically to any media outlet reaching that sad level of hopelessness.
G4 has become the Babes tab of TV channels.
Men's magazines have been in the Babes tab business for decades.