I’ve never had a tablet, or even used one for more than a minute. If I used one, my use case would be very specific, viewing full-size music scores 2 pages at once. That means 12 by 18 inches viewable, so I guess the actual tablet would be somewhat bigger than that. Am I going to wait 15-30 years for that to happen, or is it here and I just didn’t know it? If it doesn’t exist, or has an eye-popping price tag, note that I’m not at all interested in a smaller one - not even a little bit smaller. I’d just continue with the status quo - having no tablet has worked OK so far. 
Do you intend to carry it around or keep it in one place? Because if it’s the latter, you can get an “all-in-one” PC with a touchscreen monitor - it’s like a very powerful tablet, with Windows, but it has to be plugged in to work. Here’s an example with a 23.8" screen.
I wonder if there is an app for linking two tablets so they can be placed side by side, to display a facing pair of ebook pages at the same time (and a flip on one turns the page as it would in a real book) - seems like the sort of thing someone might already have invented.
No, I don’t think you can get anything that big, I had a quick look when I wanted to put scores on my tablet and found it wanting in the size department. You can get “2-in-1” computers, Dell has 15.6", but they are expensive, over $3000aud and it still isn’t as big as you mentioned/want.
Thank you - this makes sense - it’s a lot of pixels. I’m not going to pursue this any further. Even if someone says there is one, it’s obviously going to be either highly inconvenient or extremely expensive or both, so forget it. Again, thanks!
There are oddball tablets designed specifically for this purpose, but they’re expensive and I have no idea if they’re any good. Here’s a couple examples from the first page of google. They’re both single or double page A4 e-ink tablets, which means display quality will be excellent for this purpose, and battery life shouldn’t be an issue. But they’re also $1600… and at that price they oughta be able to listen to you play and turn pages automatically.
I’ve tried using my Surface Pro 3 to display public domain pdfs from imslp.org. It worked alright, but the screen is a bit small (10" x 6.6") for A4 or letter scans, let alone larger formats that are common for sheet music. Plus it was too heavy for my flimsy wire music stand. I ended up just printing anything I wanted to use.
I have a surface RT and I had the idea to try taking it to my lessons, but it wasn’t any good. Too small, and too hard to see easily (for my eyes, anyway). If they’ve already got dedicated devices, they’ll presumably get better and cheaper in time. One day…
Is it really, though? Your links indicate a 13.3-inch display with 1600 x 1200 resolution. That’s about 150 pixels per inch, worse than even the crappiest of cheap laser printers. In other words, even if you pay a fortune and buy one of those devices, the music will still look fuzzy, and it’s not like with e-books where people just increase the font size until they are comfortable.
It would be pretty easy to make an ereader app that could do this, but probably there’s an incredibly small market for it.
Well, there’s Microsoft Surface Studio, which has a 28" diagonal. But at $3,000, it’s probably well into the ‘eye-popping’ range of price tags…
Samsung tried its hand at a large tablet with the Galaxy View, but I don’t think they make it any more (they’re still for sale in some places, though).
Is there a tablet that can follow the music and turn the pages automatically? I think it ought to be possible. The two times I’ve seen musicians using a tablet to hold the music, they turned pages with foot pedals. One was a pianist (Wu Han, IIRC) and the other was the Dover Quartet, all four of whom had such a tablet.
Nabi makes a tablet with a 24" screen but it’s intended for children and comes with a lot of unremovable bloatware towards that end. It also has terrible (30min!) battery life.
Standard CRT monitors used to be 72 DPI–did you think they were “fuzzy?”
18 inch Android tablet from Samsung announced.
Some need to be pugged in, some do not - depends on the model.
There are many 12-inch Windows tablets out there, which is pretty close to the iPad Pro 12.9" size which many musicians use.
Maybe “fuzzy” is the wrong word. But fonts are designed and/or rasterized for a given size and resolution, and an 8x8 font made for a 72 dpi CRT monitor is not used unchanged for printing books at 2400+ DPI. Conversely, there is no reason to expect a straight scan of an engraved musical score displayed at a lower resolution to look super great (some information from performers who spend long stretches of time professionally staring at such things would be informative). But maybe there are some tricks the tablet can do to display the score optimally at the target resolution, especially if the original comes as an appropriate digital file, similar to the way literature is rendered.
PS old monochrome monitors could look relatively sharp compared to a similar color CRT!
I guess you could homebrew it by combining a touchscreen monitor (say, like this) with one of those little Android TV boxes