Clear: There are a few different choices under Edit>Clear. The first is clearing your undo history. Once you’ve done this, you will no longer be able to undo anything you’ve done to the photo. Photoshop will give you a warning letting you know that deleting the Undo History is permanent. There is also an option to clear clipboard contents. Clearing the clipboard will delete all of your Edit>Copy history. Lastly is Clear All. Clear All will erase both your Undo history and your clipboard.
Add Blank Page: This Edit Menu option allows you to create a file more than one page in length. This would work well for creating your own photo book complete with title pages, photos, and covers. Once you’re finished you can print the pages together and create your own photo book.
Add Page Using Current Layout: Much like adding a blank page, adding a page using your current layout will copy the settings used for your current document and create a page. This comes in handy if you’re creating a multi-page document and want to have the same background on all of the pages. Rather than creating a new file with the same background, you can just go to Edit>Add Page Using Current Layout and it will copy over your information allowing you to add text or photos to the next page.
Delete Current Page: This option will be grayed out in your menu if you only have a one page document. If you’re working with a document that has multiple pages, this will allow you to delete the currently selected page. This is a good option for you if you accidentally made too many pages, or you don’t like the way the pages flow together.