Almost all of them have already been read and are waiting for me to build something to pull the links out of Brave and download/archive/index them somehow. I've been wanting to do this for a long time, but haven't yet.
It would be quicker to manually move the URLs to a text file, then supply that as input to a tool like wget. However, you will almost certainly end up with either un-necessarily bloated files, or saved sites that don't quite work.
I still stand by the spirit of my original comment - there probably isn't enough information content in your 800 tabs to make this endeavour worthwhile.
