For your browsing pleasure, here are links to a bunch of medieval images of scribes and scribal tools.
You’ll notice that in almost all the images, the scribe is holding a quill pen in one hand, and a knife in the other. The knife had multiple functions – you can tell from the pictures that they used it to hold the parchment down. They also used the knife as an eraser – if a scribe made a mistake, he could scrape the ink off the parchment before it had time to sink in permanently.
The scribes almost always sit at nice slanted drafting tables. I wish I had one that nice! The image above is from an early 14th century manuscript in the British Library (originally found here). I like the scribe’s middle-school-style wraparound desk, and the stand he has to hold up the book he is copying from.