He feels incredibly out of his depth right now, and sort of wishes Claudius would go. He wants to catch up with Mercutio, he has spent two months thinking Mercutio was dead. Benvolio has nothing against Claudius, and does want to properly meet him, since he seems to be such good friends with Mercutio and all, but he wants that to happen some other time.

He's not going to let on about any of that though, instead happily (?) responding, "What would you like to know?"