How to merge cells in a Pivot Table in Numbers?
(EXAMPLE CELL A4, A5 AND A6 ALL TOGETHER)
Generally merging cells in Numbers is not a great idea. You can easily achieve the same visual effect without merging.
You definitely don't want to try merging cells in a Pivot Table.
If you need special formatting select the cells in the Pivot Table, command-c to copy, click once in a cell of a "regular" receiving table that you have already set up, and paste. Then edit and format in that table.
You can concatenate values in cells with the & operator (in a formula it would be something like =A4&A5&A6). Or you can use the concatenate function.
SG