Answer:
Its title means book.
What is the thing which, once poured out, cannot be gathered again?
They try to beat me, they try in vain. And when I win, I end the pain.
I have a face, yet no senses. But I don't really care, because time is of the essence.
Something wholly unreal, yet seems real to I. Think my friend, tell me where does it lie?
I break away from my pack. I create holes in my victims. I can travel for miles and then disappear. I am part of a dying breed. What am I?