British Museum EA36825

The person who made this packed quite a few ink wells (11!) onto a very small palette (only 6 1/2 inches long).  Though the palette has 11 inkwells, there are only three colors present: red, black, and yellow. The lack of more colors is explained by the text on the left side, which carries the title "outline draughtsman," also translated as "contour scribe," followed by the owner's name. Given that title, the owner was probably tasked with  laying out the design and outlining the major forms, probably for illustrations on papyrus or other small objects (a palette this small would have been nearly useless for larger works, for example on walls.) Other artists would then color in the forms. Since other artists were responsible for filling in the forms and adding color, the owner of this palette did not need a full spectrum of colors.
Regarding construction, the pen storage cavity is cut from the side and then covered by a thin lid. My photos below will maybe convey some sense of how I accomplished this. 

British Museum EA36825, cherry, with black, red, yellow inks

British Museum EA36825, walnut, with black, red, yellow inks

British Museum EA36825, mahogany, with black, red, yellow inks