I know exactly what you mean. I went to a friend's house for a cuppa and saw that she had Bryce Courtenay's Jack Of Diamonds in hardcover on her bookshelf - it was a mammoth of a thing! I had read it myself on my ereader, so it surprised me to find out exactly how big it was.

Furthermore, I was reading The Eye Of The World when my ereader needed to be charged, so I picked up the paperback, which I hadn't even touched since I started using an ereader. It's only 814 pages - quite a bit smaller than the other books mentioned in this thread! - but it was such a bother to handle. I needed to use both hands, so I couldn't set it on my lap and work on something else while I read, nor could I eat while I read... and then I couldn't find a bookmark!