The average iPad weighs about the same as 100 sheets of paper
That means that the average hardboard clipboard holding a pen/pencil and 50 sheets of paper (by no means unusual) weighs about the same as a tablet like the iPad. Now, why can't the tablet be able to serve the exact same purpose as that clipboard without forcing you to manually transfer that data later into a desktop/laptop machine?
Yes, seriously. Pounds of paper.