When you specify this option, PGPMenu will ask you what string you would like to search for, and will display every key on your keyring that matches that string, as well as all the UserIDs and signatures on those keys as well, as per pgp -kvv. It will pipe the output through the pager so you can easily view it.
If you request an empty string to search, it will wind up viewing the whole keyring, as per the menu item view keyring.
When it finishes, PGPMenu will wait for you to tell it to return to the key management menu.