my kindle is not much bigger than a paperback, 117mm x179mm. Its really easy to handle.
I never thought I would take to it as I love the feel of real books, but its great.
Have a look at the many alternatives such as the Kobo or a tablet - you can't download library books on to a Kindle. I download at least 9 books a month from my library - all free.
my kindle isnt a tablet which has lots more functions. Its just an e-reader, just for books. Its also solving my lack of bookshelf problem, the shelves are already stuffed full :-(