Notes tab, keeps track of what you do and allows you to write custom notes.
The minimap button allows you to toggle map icons and alsoopenthe journal or its main menu interface options
The notes section tooltip shows the notes you make in full
The map icon toolip will remind you of when you last found something and what you got from it
The Stats tab display basic statistics about your adventure
The loot tab lets you search through all the things you've found.
The bags tab gives a simple overview of what you have in your bags. The items are ordered by type, (this will get updates in time)