Strips

Why would Dilbert tell Bob to just eat, when they are still looking at the menus?

Dilbert's being an ass. Just because someone you work with is nice to you at work, doesn't mean you share a spark. The most polite way to thwart a potential date with someone you'd like to be friends with is to make it a group get-together... but Dilbert is a bit clueless, so Amber has obviously struck upon a novel way to whack him with the "I will never be interested in you" stick.

The reason a woman might do something like this is that she doesn't understand that it hurts a guy's ego.