Size of books depends on languages
My friend (and my teacher) Joerg once asked me that how large the Japanese translated books compared with other languages. Japanese uses Kanji (Chinese characters). Because these characters can encode several Latin characters to one Kanji, he inferred Japanese translated books are smaller or thinner than the original ones. For example, the character ``mountain'' is one character ``山'' in Japanese. But, Kanji usually needs higher resolution compared with Latin characters.
I answered the books seems thinner than original ones. I have several Shakespeare's books, and I assume these translations are as accurate as possible. Some friends visited my place impressed how small Japanese books are. But, there are some other factors, for instance, a Japanese book might be made of thinner paper, the size of characters might be relatively smaller, and so on. This is an interesting point, but, we must consider many parameters.