and do you actually learn everything in it? like will i be required to know most of the details from each concept on every one of the thousand(s) of pages?!
You would probably cover most, but not necessarily all topics in the book depending on how the unit is set out. It's mainly just for reference and you
use it as you like. It's up to you whether you want to look more deeply into a certain part of the course or just skim through it. I don't think they would expect you to do chapter/review questions from the book at all (but they might "recommend" it). I remember in MUEP maths we had a list of questions from our massive textbook that we could have a go at, but I personally didn't do many (if any, I probably only did five). My chemistry textbooks for first year were hardly touched unless I needed to check if a tute question was in there, but I'm an extremely lazy student. So yeah, point is, the usage would depend on how academically vigorous you are and whether you need to abuse books to get a better understanding of things.
For VCE books, they're tailored to cover things from the study design and they generally attempt to only include things they feel are relevant. With uni it's 'hey, we are so passionate about this subject so we're going to give you a slab of of information that you can dig through yourselves.' - also many universities probably use the same text so the book would be huge and general to cover a range of unit designs. You'll probably start to see the learning for the sake of knowledge side of things rather than for a number... well you'd hope to.
Having said that, I'm not sure if they treat MUEP chem differently to normal uni classes.