In this case, in my data, I have
Full Name Total Activities
A 1
A 1
B 4
The ideal output would be:
Full Name Total Activities
A 2
B 4
of course you can, you just pre summarize it in the source query.
So your source query would be
SELECT COL1, SUM(COL@) FROM YourTable GROUP BY COL1
and you feed that into your target table.
Of course you lose detail and can never work out what made the data in that table. It's usually a better idea to store the detail and summarize it afterwards, as has already been explained.