Firstly, everything that will be expected of you or can be thrown up on the test can be found in the standards document relating to what test you are taking i.e. P.P.L.(H)/C.P.L.(H) or F.I.(H). This will be titled "Candidates guide for the applicant of a _______ skills test.
Whichever it is, my advice would be know your aircraft inside and out, especially the emergency drills, if it is an F.I. test, you will be asked questions on some of the most popular subjects that a typical student will ask you.
Overall, you should have really learnt your subject as trying to bluff the examiner is the worst thing to do. Good luck.
FF01