The program configuration menu can be found by tapping the properties icon (see icon above) at the top of the main application window. You can then:
Create a new tab in the contact creation form like the location or notes category.
Create a new group for that selected tab.
Create a new field of input for the selected tab.
Delete the selected tab/field.
Optimize the database
Under the Categories tab you can create a category for your contact to fall under, as mentioned in "creating a new contact".