I went with a low end Samsung Galaxy Tab A 10.1, the size is good, battery is great, the hardware is not beholden to the software (i.e. no lock-in with Amazon Kindle, Nook, iPad-iOS.) Good speed and google Play certified (that's the gotcha on cheap tablets make sure you can run google play) I know it is reparable (Have fixed friends Tabs'). Has a relatively new OS (Android Nougat)), SD card slot, dual camera.m Maybe not some of the other extras of higher end tablets like IR and extra ports.
In general usage has been great, and the benefit of PDFs on a tablet is being able to zoom and scroll (Got a scan of Computer Lib/Dream Machines in it, the zooming/scrolling is very helpful to read it.) Though if I had a choice I would prefer paper books if available the screen can affect your reading and also light reactions staring as the display closer than a monitor.
Beyond that I'm not too impressed by the ebook stores "buying" ebooks though them is no discount (plus you get the added dread of the e-book outlets still have complete control your "purchased" - er licensed content).
library ebooks are nice, and also magazines (though library e-editions seem more ad-riddled than print ones.)
Tablet apps are pale next to desktop stuff, and you may have to hunt to find tablet stuff that actually are comparative to good desktop FOSS.
In hindsight I like it, I would not have found more value in the bigger screen of a page size (except more heft and expense)
If unsure borrow a friend's and try it out. Though if they only have the supplies PDF viewer, I would get acrobat or some other more capable PDF reader to test the built-in ones are usually kinda lacking.