From Liam (5.07):

It occurs to me that jerome would have had the
ink pot on the left side if he was working on the kind of complex
illustration common to this kind of work in the middle ages
(decorative letters often used to begin passages) . If the
illustration was on the left side of the page then it makes sense to
keep the ink pot close to minimize the risk of dripping ink on the
page. This is pure speculation by the way, I dont know whether did
these illustrations himself or merely did the translations.