I like to read dozens of comic strips every day. I bookmarked all my favorites and put them in a “Comics” folder mounted on the Chrome toolbar where I could command-click to open them all at once, and then hit command-W after reading each one.
A few years ago Chrome started to slow down so I switched to Safari. When that began to refuse to mount them all without rebooting the iMac, I switched to Firefox for this one job. Works like a charm.
So if you have a bunch of tabs you want to open at once, give Firefox a try,