The flat slab humanity invented twice: once for laws, once for Netflix in bed.
means Flat, portable slabs used for writing, recording, or—in the modern sense—a touchscreen computer larger than a phone but smaller than a laptop.
from From Old French 'tablete,' a diminutive of 'table,' which traces back to Latin 'tabula'—a board, plank, or flat writing surface. The word literally means 'little table,' and it has carried that sense of a flat slab for marking things down across millennia: clay tablets pressed with cuneiform, wax tablets scratched with a stylus, stone tablets carved with commandments. The pharmaceutical 'tablet'—a flat compressed disc of medicine—and the digital tablet both inherit that same ancient idea of something small, flat, and meant to be held.