Eh, em. I think we call them Flying Aptitude Tests. It's to see if it's worth a Flying Instructor's time, at a Flying School, to engage you in Flying Training. The Americans, of course, think differently.
It's worth noting, incidentally, that the RN doesn't recruit pilots; or didn't 40 years ago. They select officers who will specialise in flying, in the same way as some will specialise in underwater warfare.
Read the advice of noemis. Do anything that might speed up your reactions and anticipation. Similarly for things that exercise your hand/eye(and foot) coordination and ability to monitor several things at the same time and detect change. Also learn as much as you can about aircraft and how they fly and are controlled. If you looked at a picture of a "blind flying panel" (altimeter, ASI, VSI, turn and slip, artificial horizon, direction indicator), would you have a mental picture of the aircraft's attitude and condition of flight?
Best of luck and trust your own judgement and abilities.