Other than rulers, styluses, ink mixing plates and other writing tools, since a hypothetical true writer would need to know so much of the natural sciences, I'd expect anything you'd find in physics/geology/biology/chemistry/etc university labs. Pulldown maps, charts and diagrams, walls lined with cupboards containing various demo experiments. Maybe make the inkwells part of the tables? :7
Slightly off topic:
How DID they make that ink anyway? Did they really grind up beetle shells, or is it rather that the beetles are indicators of suitable plants, which they like to nibble on? I mean, assuming the first case and given the use of beetles in the gahreesen reception area, would that make them cannibals...? :7
Hmm, wasn't there something on the topic in Achenar's last diary in Revelation...?