I'm with T250. This isn't primary school, you are applying for a job and you're potential employer has sent you a document (which really isn't that long and doesn't contain that much information) and advised you that they are going to test you on it. If you want the job then surely it is obvious that the more you learn the more impressive a candidate you will be.
I'd also point out that NATS are just as interested in your attitudes and work ethic as they are in your innate abilities and aptitudes (if you are fortunate enough to get through to stage 3 you'll get grilled on this much more thoroughly at interview). Are NATS going to test you on every minute little detail? No, of course not. On the other hand, if one candidate knows it well enough to correctly answer any question you might choose to ask on it whilst another has only a loose overview and clearly hasn't bothered to commit themselves to learning the details, which one do you think they are likely to pick? The latter candidate has clearly demonstrated a positive attitude and shown that they are willing to work hard to get somewhere in the life, whilst the former candidate has only put in the minimum effort required.
If the attitude you demonstrate to NATS is that you are only prepared to put in the minimum amount of work to get the job then how will they be able to have confidence that you are going to pull your finger out at the college? (where you will have to learn a lot more information in vastly more detail - have you had a look at MATS part 1? It's over 400 pages long and you will need to know the majority of it in intimate detail before you graduate the college).