It's easy. Place a TAdvColumnGrid on the form and place 2 buttons to add or remove rows.
Below the onClick buttons events.
At the first click to remove rows (only at the first click) disappear 2 rows, not 1. The rowcounter decreases by 1.
procedure TForm1.BitBtn1Click(Sender: TObject);
begin
AdvColumnGrid1.InsertRows(2,1);
end;
procedure TForm1.BitBtn2Click(Sender: TObject);
begin
AdvColumnGrid1.RemoveRows(AdvColumnGrid1.RowCount,1);
end;