You can't add a row at the start of the table.
AddRow automatically inserts rows at the end of the table.
However it is possible to use a hidden column containing an index value.
You could then insert a new row and sort the table using the unseen index.
This is I believe the recommended approach to take.
This is true, and has been reaised a few times here within the Forum.
the solution is to either filter the table each time you load from the file, OR, you can create a new tabel copying across the cells from the filtered table and then save this to your file.