I think that IkkeEnGij's suggestion will be your best approach, going forward. If your users are starting to see the need for analyzing information in Table B then you should address it now rather than when the number of such requests has grown.

But, if you insist on maintaining the status quo, perhaps you could create a view in the database that normalises the data.

Something along the lines of this air-code

CREATE VIEW TableC AS
SELECT Employee1 as EmployeeID, Column1, Column2, etc
UNION
SELECT Employee2 as EmployeeID, Column1, Column2, etc
UNION

etc., etc....