Some of the earliest tablets from mid- to late-3rd millennium BC were painted slab stelas.
A small number 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.
From the middle 3rd millennium BC, some famous horizontal lintels were made.
This article about subjects relating to ancient Egypt is a stub.