This is my DMing seat at the end of the dining table. On the right are large-scale maps and other things I only have to look at every once in a while; on the left are books that are going to get pulled out in play for reference, but which don't have to stay open. The irregular space beyond that is dice, miniatures, etc., plus of course where I keep my drink and stuff.
So the empty space in the centre needs to contain whatever I need at any one moment -- that is, it should have the info I need for a given location plus the stats of any items or people in it.
I can fit an opened book into the space if I need to, so the maximum size should be about A3.
But this sideways A4 pad fits much more neatly. So two pages of an A5 notebook would work well, or an A5 book like the excellent Forgive Us. Only problem is that most small A5 books, which is what you'd typically get with a shortish adventure, don't lie flat.
Or an intermediate-sized book like my recent acquisition (eagerly reading right now, full review coming soon), Maze of the Blue Medusa.
|And it lies flat, has colour-coded page edges, has a bookmark, crucial maps frequently repeated ...|
So let's say that the ideal structure for Magonium Mine Murders is something like this: you have the booklet, and the booklet contains the background, the detailed rules stuff, all that sort of thing. And then you have a series of single sheets, sort of like one-page dungeons (I see that there are collected volumes now available on DTRPG: 2015 and 2016).
If it's a PDF, that actually makes more sense -- you have your reading thing and then you have your one-sheets you can print out and bring to the table. Hmmm.
OK, this is all worth thinking about.