I’m not quite sure how Norton has managed to super-size his already enjoyable talk show this season, but it’s been ridiculous, and ridiculously entertaining. What makes his talk show unique? For one thing, and it’s no small thing, he invites most of his guests out at the very start, so that, recently, Sir Paul McCartney sat next to Katy Perry for the entire show. And tonight, the seatmates include another Sir, as well as a Dame: Elton John and Judi Dench.