It's usually in place of breakfast and lunch, as it's too late for breakfast and too early for lunch, so we call it brunch.

I spilt coffee all over my new dress this morning! I'm cheesed off. C.H.E.E.S.E.D O.F.F means I'm really annoyed.

A few bob actually means a small amount of money but it's usually used in an ironic way, to mean a lot of money.