
Put a pane of glass in the second slot and you’ll get a “locked” map that can’t be explored any further. Put an empty map in the second slot and you’ll get a clone of the first. Put an explored map in the first one and some paper in the second, and you’ll get a zoomed out version that covers more territory.

Hit the "use" key on the table and you’ll get an interface with two slots on the left. So what can you do with it? Well, quite a lot actually. Put two bits of paper on top of four planks in a crafting grid, and you’ve got yourself a cartography table.

Cartography tables generate naturally in cartographer houses in villages, but honestly, it’s usually easier to just craft your own from some paper and some planks.
