URxvt has tabs, via some sort of plugins. There are (at least) two "Perl extensions" for it.

    urxvt -pe tabbed
    # or
    urxvt -pe tabbedex

Tabbedex needs to be installed, it has more features than `tabbed` (which is bundled with rxvt iirc), eg. tab renaming and moving. Looks like this: https://vgy.me/S1j8Re.png