Having gotten a H3 in MAST20004/Probability in undergrad I was worried about this subject so decided to get it over with early on, but fortunately it turned out to be nothing to worry about. Some of the content can get a bit tricky, but overall if you persist and keep up with the problem booklet/lectures, the exam and test/s are mostly doable, at least with Brian taking the subject. Handbook provides a pretty good overview of the content so I won't re-list that here. Brian was also a really great lecturer who explained things in good detail and provided a few extra materials for harder concepts/questions.
My favourite part of this subject was probably the workshops. Despite the name, as mentioned above they were basically assignments which had a dedicated workshop where you'd normally get assigned a partner and start to work on it together (this didn't happen during this semester, but in normal circumstances I highly doubt you'd have enough time to finish it all in the session), then it'd be due a week or so later. They contained a mix of theoretical and MATLAB questions, the latter of which mainly involved setting up simulations. Most people doing this subject would be coming from the BSci Electrical Systems major where Engineering Computation/COMP20005 would have been compulsory, but if you were one of the few people like me who didn't come from the standard pathway, make sure your coding skills are up to scratch unless you want to be relying on a workshop partner. However, having fortunely done COMP20005 as a breadth in undergrad, a decent understanding of this subject would be more than sufficient for the skills required for the workshop MATLAB questions. The simulations meant that you could pretty much verify most your theoretical calculation answers, so while these workshops were usually pretty time consuming, getting full marks or close to it was very doable.
For weeks when there wasn't a workshop assignment, the timetabled workshop session pretty much became standard tutorials where you'd work on problem booklet questions and could ask the tutor for help which was quite helpful, especially before a test or the exam.