The recently viewed menu combines 2 useful functionalities, it is a history list to jump back and forth to recently viewed pages and it is a bookmarks menu to save pages which are frequently visited.

Each unique page that is visited will show up on your recently viewed list (the list is personal for each user).

If you would like to bookmark an item you can click the star icon which appears next to each item on the list.

Bookmarked items will be always on top of the list.