1. Page details
Page name, Page URL & parent page please see Article "Creating a new page" (step 3-5), Design template is not editable it shows what template the page is created from.
2. Meta tags
Meta descriptions & meta keywords are optional input fields, are advisable for Search engines like Google, Bing & Yahoo (SEO tools).
3. Page title
By default the page tile is done globally in the settings page, but you can override this on a page by page basis. This is good if you are optimising a page for a search engine key word or phrase.
4. Layout options
If your "Design Theme" has a "Left panel", "Right panel" or both. you can switch them of on a page by page basis for example if you have a right panel that contains a second level menu in it you may not want to show that on the homepage, so you have full width content.