in English it is a general term saying you will punish someone strongly if they do the wrong thing. "Throwing the book" = strongly enforcing rules. If he keeps coming to work late, his boss is going to throw the book at him. You have been fined for speeding three times. If the police catch you again, they are really going to throw the book at you.

I found this online, too: "To throw the book at (someone) is 1932, from notion of judge sentencing a criminal from a law book full of possible punishments."

I am guessing that you are referring to an expression used in legal settings such as a courtroom. It means that the judge, for example, sentenced an individual to a pretty severe punishment. The judge was not lenient and "threw the book" at him (the criminal).

The expression is ‘throw THE book’ meaning to charge someone with the highest number and most severe crimes possible given the wording of the laws in the penal code. Otherwise it would be interpreted literally. My wife threw a book at me to get my attention. I threw the book I was reading at the coyote who was threatening my dog to scare him away.