I got asked about various things near to the planned route (e.g. what does this symbol mean on the map? what would you do if your route took you through it?) and a few M&B questions (what would you do if we were to take a passenger? If he is on the rear seats, where would the CG move on this aeroplane?)
But really don't worry about it. Its nothing too technical. All the CAA examiners are there for is to make sure your not going to kill yourself and (More importantly) your paying passengers. Its all very "real world".