Those big books are your name and home address which were used to make sure you were in the correct voting location. Then you signed the book in front of the b

Those big books are your name and home address which were used to make sure you were in the correct voting location. Then you signed the book in front of the ballot person as a sort of "proof" the information was correct and you were voting. So basically, it's just an honor system. One could theoretically vote in the morning under your real name, then come back in the afternoon and vote again as your neighbor - so long as you beat them there.