This may help.

https://news.ycombinator.com/item?id=34847611

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.

> The browser should remember the date you last rendered a tab, and then if the link rots, it falls back to archive.org on that date.

Brave (by default at least) will ask you if you want to load the archive.org version when a page fails to load. Not 100% automatic but almost.