This is the Alerts tab of the Visit Editor. See Concepts - Alerts for background.
 

The buttons are as follows:
OK - save any changes and close the Visit Editor
Cancel - cancel any changes and close the Visit Editor
New - create a new alert
Edit - edit the selected alert
Delete - delete the selected alert. This will display a confirmation window. Select OK to delete the alert, or Cancel to keep it.

This screen is very similar to the Patients - Medical Records - Alerts tab - see this for further information.