Open

This displays a list of recently opened files.
The shortcut keys (Ctrl + F12) and (Ctrl + O) will quickly display the Open dialog box
You can pin a file to the list by hovering over it and clicking on the pin.
Any pinned files will stay at the top of the list.

Recent Workbooks - Displays a list of the workbooks you last opened.
OneDrive - Lets you open a file from OneDrive.
OneDrive - Personal - Lets you open a file from OneDrive.
Other Web Locations -
This PC - Displays a list of recent folders and a Browse button allowing you to browse to any folder.
Browse -
Add a Place - Lets you add locations from SharePoint or OneDrive.