Slab_stele
The slab stela was an original form of the steles of ancient Egypt. However, it was horizontal in dimension. Some of the earliest tablets from mid- to late-3rd millennium BC were painted Slab Steles. A small list of Ancient Egyptian dignitaries or their wives had a slab stela.
Some funerary stelas were in the form of slab steles, as opposed to being of the more common vertical type.