[bergie]

Theoretically you could use a portable HDMI screen and a battery pack, but that's quite clunky.

The Galaxy Tab S4 supports DeX right on the tablet AFAIK.

[DennisAleynikov]

The Tab s4 and s5e both have DeX mode on screen and can be proto-laptops. Also there exist lapdock implementions by favorite being the HP Lapdock which even supports wireless pairing (Although DeX still needs to enable wireless projection mode)