In public libraries in the UK people tend do this kind of work in the so-called reference library, which has desks, often with power points for connecting laptops. A similar set-up exists in Univeristy Libraries. If there are separate rooms, I think it's likely they'll be called 'quiet study rooms', or 'special study rooms.' The British Library has a number of large reading rooms, more or less exclusively filled with desks and a small number of books on display. Books are otherwise requested and brought up from the basement by staff. My suggestions are more generic than 'scriptiewerkplaats', but that doesn't mean people woudn't be writign their thesis etc there!