Do ask. You can phrase it as 'Ahead of the exercise on Tuesday is there anything that I can prepare for in advance?' Or similar.
I've administered many written test, and taken them as a candidate. They're usually closely linked to your role, and will likely be in several parts, each testing something slightly different, eg 1. Analysis 2. Presentation of a decision with data to support 3. Prioritisation based on business need.
If you've had an interview previously look over your notes, what were the priorities of the team, why do they need your skills?
Also do show your workings, eg I was well marked when I showed the reasons I'd discounted other options as well as explained why I had picked the option I did in an analysis question.
Finally, don't be surprised if there is too much to be done in 2hrs, it's a test of how you can cope under pressure, can you cover all questions to a reasonable degree rather than just one but aim for perfect.
Good luck