There used to be an addon, “Open tabs from clipboard URLs” but I can’t seem to find it anymore.
The best I find now is, an addon that opens a box, then you paste your URLs in it, then you press a button.
That’s not what I want. I want a toolbar button, I press it, the tabs open.
So that I can opens large blocks of URLs.
Also, I would like another addon which opens large blocks of URLs but does not load them immediately.
I have LoadOnSelect3 for this, but the problem with that one, is that it opens special moz:// pages until you load the tab. And that breaks searching and filtering tabs because the tab title and URL are not the real ones.
Two potential solutions to x in this case might be
if the links are always the same, save them as bookmarks in a folder and you can right click to open all in new tabs
if the links are all different, I think there are tools that can do that (spreadsheets, scripts)