This is the 10349th most frequent Turkish word.
bilmek
"Bilmek" means "to know."
Here, 'bilmek' is used in its standard form to convey the action of knowing a fact or information.
Ben doğruyu bilmek isterim.
I want to know the truth.
'Bilmek' here signifies familiarity or recognition with the book, something that is well-known or understood.
Bu kitabı çok iyi biliyorum.
I know this book very well.
In this instance, 'bilmek' is used to describe the act of being aware or informed about someone's feelings.