Use this dialog to edit the parameters of series:
The button <Remove> lets you remove all series.
The button <Function...> starts the Wizard of approximation on all points of series.
The button <Copy points> lets you copy points selected in grid and put them on the Clipboard.
The button <Remove points> lets you remove from series points selected in grid.
The button <Editor...> lets you you call the Text editor to edit X,Y,Z values.
Trick: Click on header of grid to sort points by X, Y or Z.