If you press F12 or Ctrl+Shift+i (or Mac equivalent) you’ll see the Developer Tools for your browser. If you go to the Network tab of this and press Ctrl+Shift+R you’ll see every file that is loaded and the size of each file. Your webpage/Space here is 96.8MB! Most of this is taken up with your student’s work, with most images being ~7.5MB (see img below). To put this in perspective, most webpages aim to be < 2MB.
These images don’t need to be that big in image size. I suggest reducing the pixel size of each image via Paint or Irfanview first, then optimising via https://tinypng.com/ and replacing the ones that are there. I reduced this image from 2048 x 2048 px to 800 x 800 px, then optimised, and reduced it from 7.5MB to 574KB.
Hope this helps!
Geoff @ TechLeap