Osmin :
People who are legally blind prefer the largest screen tablets available and speed is not an issue. The 18.4" ASUS P1801-T-B016M tablet was on sale at newegg.com after the holidays for $529 and now it is $559.99. It is the largest tablet that I know of and works well for the visually impaired.
This is not the largest. HP has one 21" Android tablet selling for $400. Yes so cheap. Anyone who loves a big tablet can consider this.