I have a Levenger "editor's desk", which is close to a mini-drafting table that sits on top of your desk. It gets a little iffy, though, at the start or end of

I have a Levenger "editor's desk", which is close to a mini-drafting table that sits on top of your desk. It gets a little iffy, though, at the start or end of a book, where the "thin side" of the open book doesn't have enough mass to hold itself down. What I found that helped with that were the giant rubber bands you can get at art supply stores, that are typically used to hold things to a drawing board. Two of them around the editor's desk do a fine job of holding a book open, bands stretched across the top and bottom margins.