Well, according to Wikipedia, the history of tablets goes back to the 1800s. But I know for a fact that I bought two tablets on December 31st, 2011 that were priced at $2000 (after getting a 2 year internet service contract plus a 20% employee discount to reduce the price, I paid $800 up front) and it was kind of the hot new item at the time. And I know for a fact that proliferation of apps we have now was not the norm back then. I had enormous difficulty getting things done on it and I noticed that painfully because I essentially had no other access to computers at the time. I can now do all kinds of things on a tablet bought for under $50 that I could only dream of and wish for 5 years ago.
https://en.wikipedia.org/wiki/History_of_tablet_computers
Humorously:
"Mobile to overtake fixed Internet access by 2014" was the huge headline summarising the bold prediction from 2008 by Mary Meeker...
http://www.smartinsights.com/mobile-marketing/mobile-marketi...