Tapping the Load Tuning button in Settings brings up a list of your stored tuning files, similar to the iPhone "Contacts" application. Initially the list contains all your stored tuning files in alphabetical order. You could just proceed to finding the file you want in that list and selecting it to load that tuning and return to the main tuning screen. But if you have a great many tuning files, it might be quite tedious to find the tuning file you want.
To help you find the file you want to load, there is also a text field just above the list. You can use that text field to search for only those files that match the portion of the name that you enter in that text field. Every time you enter a character in the text field, the list of tunings is revised to show only those names that match what you entered.
When you select a tuning file, VoiceOver will speak the name of that file and how many names there are currently showing in the list. This can help you decide if you need to limit the list further by entering a more complete portion of the name in the text field.
When you activate a name from the list, that tuning file will be loaded into memory and the software will automatically switch back to the main tuning screen, where you can begin tuning.
In addition to selecting a tuning file to load, this list of tunings serves another purpose. It makes it possible to delete a tuning file.
To delete a stored tuning from your device, use the Edit button in the top right corner of the screen. This will put a delete control in front of every name on the list. Find the file you would like to delete and active its delete control by swiping to the left. VoiceOver will announce the selection of the delete icon as well as the name of the file that is considered for deletion. Then a separate confirm delete button will appear on the right side of the name in the list, and it will be selected automatically. Double tap to confirm this deletion. This involved process is designed to make it difficult to delete a file by accident. VoiceOver does a good job to clarify what you are doing in this process. You can delete any stored tuning, except the pre-packaged "AVG" tuning. That tuning is protected from deletion or overwriting, so that you can be sure it is always exactly the same as it was when the software was first installed.