Yes, but it is a fantastic solution...
In a technical sense. But the price point is excessive for this one use case.
It is a fantastic tool for the job and allows me to carry literally thousands of books with me all the time.
Which, of course is way more than you'd need in your entire life, so, who cares? We don't need it to carry thousands, We need it to carry maybe a couple dozen at any given time.
Function in excess of need is not a rational selling point. It is like trying to sell me a Lamborghini when 90% of my driving is to go to the grocery store 3 miles from my house.
A big tablet is a fie piece of hardware, with many technical capabilities. But if all you're going to do is look at a few RPG pdfs, it is turning a cheap hobby into an expensive hobby.
If you need a device that you're going to use every day, for several things, then paying $500 to $1500 on a huge tablet may be a rational solution. Or, if you are simply wealthy, so that dropping $500+ on a thing you'll pick up only once in a while isn't an issue for you. But, I suspect most of us are pretty middle class folks, for whom that's not chump change.
Upthread, I mentioned that I do most of my fiction reading on an e-reader these days. Note that this e-reader was a gift, and runs under a hundred bucks, and I use it pretty much every day. That's great cost for use. A 12" tablet just for game pdfs? Unlikely to have the same payoff.