Error code: SBOX_FATAL_MEMORY_EXCEEDED whenever I try to open my week 3 lab I recieve this message and the browser crashes

That error looks like it is being thrown by your browser, not by the Coursera website. Note that the memory images of the notebooks can get large if you put voluminous print statements in your loops. Have you tried restarting your browser and opening just one tab with that notebook? What you need to do is get the notebook open so that you can do “Kernel → Restart and Clear Output” to reduce the memory footprint.