A Library gets big. This is how you work on a lot of it at once. Select turns the grid into something you can tick. Choose what you want to act on, and the bar keeps count. Then act on all of them together. Move, tag, or clear out. File them into a Collection in one move. Three moved, and the grid hands itself straight back to you. Tag them the same way. The tag lands on all three, and turns up down the side to get back to them. And clear out what you no longer want. Delete asks first, because this one does not come back. Escape when you are done. Down the side are the ways back in: starred, set aside, and every tag you have used. Same Library, still yours, and easier to walk through tomorrow.