Here's the best that I have. Open a Folder in Bookmarks. Load the URLs into the Folder. At the bottom, under a line will be "Open (all) in Tabs." For me they all open almost as fast as just a single one. They will open open one at a time so you will still need to click on the new tab to get it to open. Not exactly what you wanted but ...
Good Luck, JP 🙂
