An extension like Tabs Menu 1.4.8.1-signed.1-signed.1-signed
https://addons.thunderbird.net/seamonkey/downloads/file/21797/tabs_menu-1.4.8-fx+sm+fl.xpi which places Tabs as a menu item would be very usefull.
Tabs Menu allows one to scroll down a list of tabs and switch to the tab you select.
In K-Meleon this could be done with just a macro because under View menu item Tabs is listed as a sub menu item