I don't know, I think a 7" tablet would be too small to read an Eclipse Phase book without a lot of panning and zooming, which gets old really quick. The new iPad has a much larger display and is high enough resolution that PDFs look like print, and you can read an entire EP page without any zooming. Get the iPad

Things may have improved a lot lately with tablets, however depending on price a good laptop will still outperform it. I have an Acer Iconia A500 (so one of the first generations with the tegra 2 cpu etc), and it suffered a bit with the PDFs, in particular searching, and suffers horrendously with pdf versions of the Dark Heresy and Pathfinder books. Also, spreadsheets such as the excellent character creation ones available for EP don't work too well on it. I've gotten myself a little Ultrabook from HP lately which is seriously quick, and handles it all fine. Touchscreens are a bit annoying for typing notes etc quickly, but a bluetooth keyboard helps alleviate that problem. Your mileage may vary of course :)

I'm going to be banned for this... XD I use a low-end 2 years old BQ Darwin with Android 2.3 (a custom version, since the company stopped taking care of that model long ago). It has an 8'' resistive screen (that is, use your nails or something like the Game Boy's pencils), and while it is a little slow, I can read the books quite well. The only trick, which should work with a 7'' tablet (like the Nexus 7, for example) is to place the device horizontal and read up to down. Not ideal for game consulting, of course, but the search function should help a great deal. That being said, if you are carrying stuff for the game, a 10'' tablet will be better, and you will be using a backpack anyway (dice, pencils, paper, etc...), so the main advantage of the smaller tablets (portability) is not really relevant. Personally, when I have to carry a backpack I use my 10'' notebook computer directly.