After marge table total value increase

Hi,

I marged two 2 excel files with id value(left join). after marged in my matrix table my total is getting high. For ex- 

in my table 1 total candiadte is 10. when i marge the table 1 with table 2 and expand the column, total candiadte is showing 17.

How to resolve this problem?

Thanks in advance.