[Quoth]

You already have a 10" Android tablet. The only thing better is a 12" to 14" one.
For PDFs I use a 10" Lenovo (originally nearly €200, but reduced in a sale. I added a €40 256G Byte µSD card) and my wife uses so called fake RCA* branded €88 10" tablet from Tesco that also has a 32 GB µSD card bought separately. Much better than the laptop as it's portable, though the old 1600x1200 laptop bought in 2002 was better for PDFs than the late 2016 replacement.

* Edit: RCA is defunct since 1986. Thomson certainly bought the label, but the RCA branded tablet seems to be made by someone else, though it's probably a Chinese OEM sold by a UK marketing company. Tesco in Ireland often sells products that have only UK support.