Not for this reason, but I use Singlefile to save pages to a Single HTML file with the original formatting, maybe that's what you are looking for. Basically it discards the tab to disk. When you reopen it later, it won't be interactive anymore, though (maybe certain settings can help with that).
Added bonus is that this way you are making archives for yourself. The files are often relatively small. I have set it up to download to a subdir of Downloads, and set that dir to compress files so that it's even smaller, and from time to time I repack all of them into a 7z file where their size is really negligible.
Other than that, I don't know of a way to basically "hibernate" a tab. That would be pretty cool to do, though.