The list of Scheduled calls available on the Calls tab gives an overview of the upcoming customers who have been automatically scheduled to be called again. This list is sorted in order with the customer who will be dialled automatically at the time scheduled first at the top. This list will only show agent specific Scheduled calls. This is only available if you have a personal Queue or marked the Scheduled call as agent specific when it was set.
Clicking on an upcoming Scheduled call will show the available actions and you can click the Phone icon to call the customer immediately if you need to call them before the scheduled callback.