So the pieces are there, but not structured in a way for a database to quickly access the data you need, or to allow growth without major restructuring.
In your case the best way to do that is to arrange the data in a longer format instead of the wide format you have. So instead of having each column represent an entity identifiable only through a metadata ...
As i said in the comment simply Replace the SUM with what ever you need in your
Create Table `data`
Insert Into `data` (`callDate`, `callerName`, `callLength`) Values
('07/01/2020', 'Client A', '0:00:23'),
('07/01/2020', 'Client B', '0:15:23'),
('07/01/2020', 'Client C', '0:7:10'),