My experience with iPad is that it is "heavy" more because of the way one uses it/interacts with it, than how much it weighs. The pad is very stressful on the wrist with prolonged use, and must be placed on a desk.
It's similar to compare the way we read books - by placing it on sth. and then flipping the pages - so even for heavy books we do feel not that "heavy". If one has to hold a book for extended period, it feels heavier.
Without special sleeve/cover, the iPad is very hard to get a firm and non-stressful grip. That's one product design factor not catering to the physique of orientals. It's also why the 7" tablets from Samsung hit the market with the right niche. That's more or less the grip of a paperback book.