A few more levels on it and Carl can start building Katia real ammunition.
The sapper's table survives Mordecai's rearrangement of the crafting room and gains a stated roadmap. Paired with the new Bolt-Thrower's Workshop, Mordecai says that once the sapper's table is up a few more levels Carl will be able to build Katia Grim some great ammunition. It is also the bench behind the landmines and heal-infused smoke curtains Mordecai is impressed by — items Carl actually got out of the The Dungeon Anarchist's Cookbook, a detail he does not volunteer.
A cluttered bomb-maker's bench, relocated in the reorganised workshop.
Carl's bomb-making station, and the bottleneck on Katia's future ammunition.
Also appears in books you've already read — spoiler-safe to their endings: