I agree with you, but in the case that you have defined functions in target table, it is not possible to add any additional data without some kind of "buffer" area which should store previous data. Concept as you explained above supose that you have data (not functions) in seasons stats table. In this case you can define macro to add results from corresponding cells of weekly stats to seasons stats as simple addition. If you need to preserve functions in table of seasons stats, you can just correct data in "buffer" area. Open my sample, it is triggered with button also, and you can hide ghost table if you not like to see it.
Regards,