Based on the information that is found in the following verses, it appears that the Lamb's Book of Life is a separate Book that is opened during the Great White Throne Judgment. The other Books which are opened appear to be Record Books which contain all of our deeds in this earthly life. No matter what one has done in this current life, in order to be found written in the Lamb's Book of Life, he must have accepted Jesus Christ as his Lord and Savior, because this is the only way to blot out our sins before our Heavenly Father.
"A fiery stream issued and came forth from before him: thousand thousands ministered unto him, and ten thousand times ten thousand stood before him: the judgment was set, and the books were opened."
Daniel 7:10, KJV
"And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works . . . And whosoever was not found written in the book of life was cast into the lake of fire."
Revelation 20:12, 15, KJV
"[To the chief Musician, A Psalm of David, when Nathan the prophet came unto him, after he had gone in to Bathsheba.] Have mercy upon me, O God, according to thy lovingkindness: according unto the multitude of thy tender mercies blot out my transgressions . . . Hide thy face from my sins, and blot out all mine iniquities.
Psalm 51:1, 9, KJV
"Yet, LORD, thou knowest all their counsel against me to slay me: forgive not their iniquity, neither blot out their sin from thy sight, but let them be overthrown before thee; deal thus with them in the time of thine anger."
Jeremiah 18:23, KJV
"And I intreat thee also, true yokefellow, help those women which laboured with me in the gospel, with Clement also, and with other my fellowlabourers, whose names are in the book of life."
Philippians 4:3, KJV
"He that overcometh, the same shall be clothed in white raiment; and I will not blot out his name out of the book of life, but I will confess his name before my Father, and before his angels."
Revelation 3:5, KJV
"The beast that thou sawest was, and is not; and shall ascend out of the bottomless pit, and go into perdition: and they that dwell on the earth shall wonder, whose names were not written in the book of life from the foundation of the world, when they behold the beast that was, and is not, and yet is."
Revelation 17:8, KJV
"And there shall in no wise enter into it any thing that defileth, neither whatsoever worketh abomination, or maketh a lie: but they which are written in the Lamb's book of life."
Revelation 21:27, KJV
"And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book."
Revelation 22:19, KJV