Apocalypse Revealed #274
274. Now when He had taken the book. (5:8) This symbolically means, when the Lord prepared to execute judgment, and thereby put back into order everything in heaven and on earth.
To take the book and open it. This symbolically means to explore the states of life of all people and to judge each one according to his state, as we said before. Consequently His having taken the book here means, symbolically, to have the intention to execute a last judgment. And because He executed a last judgment in order to put back into order everything in heaven, and through heaven on earth, this too is symbolically meant.