Merging forms with different structure is very complex area, and really out of the scope of the functionality provided by ConfiForms TableViewMerger, but here is what could be done...

Data in form f1

Data in form f2

Merging together, text field (same name) is as the grouping key

Merged column is configured like this 
Merged:(ZEROIFEMPTY("[entry.myfield2]") + ZEROIFEMPTY("[entry.myfield1]"))