Inkwell

An inkwell is a small jar or container, often made of glass, porcelain, silver, brass, or pewter, used for holding ink in a place convenient for the person who is writing. The artist or writer dips the brush, quill, or dip pen into the inkwell as needed or uses the inkwell as the source for filling the reservoir of a fountain pen. An inkwell usually has a lid to prevent contamination, evaporation, accidental spillage, and excessive exposure to air. A type known as the travelling inkwell was fitted with a secure, screw lid so a traveller could carry a supply of ink in their luggage without the risk of leakage.

Inkwells gradually fell out of use in the early part of 20th century as the reservoir fountain pen (which needs to be filled only occasionally) replaced the dip pen, which needed to be dipped in ink after writing a few lines. Holes known as inkwells are a common feature of old school desks, and would have held a small container with the student's ink.

...
Wikipedia