Thanks for this. Can you please add a keyboard shortcut? Thank you.

It's simple and convenient, but I just want a keyboard shortcut. And I don't like icons.

Does the job. This should be a Firefox keyboard shortcut. For instance, in the Calibre editor, Ctrl-W closes one tab like in Firefox, Ctrl-Alt-W closes all open tabs except the active one. I would be happy with the same shortcut in my browser. And maybe something to close all tabs and clear the cache…