Located in what one might call the master bedroom, this table appears to have been for the grown-ups to do their writing. There was a small room (and I do mean small, more like a solitary confinement cell in fact) at the opposite end of the bedroom which contained another "desk", though that term is putting it generously. If I were to guess, that room would be for the child of the house (or if more than one, one of them at a time) to study without distractions, but that's speculation on my part.
This desk would probably have been too large for the children and appears to have the more expensive beeswax candles rather than the lower quality tallow one seen in image 18211. This suggests that it was for secret grown-ups business.