Does thhe Martinverse has something similar to the Star Wars Essential Atlas.
Something examining the Lore of the world.
There's at least one book coming out soon, and another later. There's The Lands of Ice and Fire
, which will be a world atlas (released at the end of the month) and World of Ice and Fire
, which is supposed to be a companion of sorts, although there is no solid release date for this, nor would I guess there is likely to be until GRRM gets close to finishing the series.