Many people here are talking about buying an iPad and the pencil, but if all you’re doing is reading papers I think this is a massive overspend. There are many inexpensive android tablets that come with pencils plenty good enough for handwriting or non-artistic drawing.
Of course, you say you have a job so you’re likely not to need to buy the cheapest thing possible (even if you don’t, you’re not forced to buy an iPad, Samsung’s tablet software is quite good), but I don’t want someone with the same use case, who might just be a student, to get the impression they need to spend a grand to read pdfs.
Interesting article, the statistics section was quite surprising. I wonder if there were as many fantasy books in school libraries before harry potter came out.