In list screens like this, you manage application data that can be used elsewhere in the system. In these screens you add lines of information which you can activate and deactivate.
Each screen of this kind initially shows the list without inactive values. You will see inactive values by through the including inactive checkmark. You can edit each value's activity with the button at the end of each line.
To create a new value, click on the floating plus button at the bottom right of the screen. If this button is not available, you will first have to fill in a filter.
After you have finished your adjustments, you commit them with the save button at the top right of the screen.