Four hundred pages in one file, your professor clearly hates tablets. I had the same thing in my second year and ended up using Convert2PDF. Their Split PDF tool lets you either extract a specific page range, say pages 120 to 175 for one topic, or split every page into a separate file. No account, no trial nonsense. Since the processing happens in your browser, speed depends on your device: on my laptop the full file took a few seconds, on an older tablet it was noticeably slower. So I’d do the splitting on a computer and then move the files over. If you need the full set later, you can always merge chapters back together with Merge PDF. You can also remove pages you don’t need, like empty title slides, to make each chapter shorter.
