Actually, as Jim mentioned, this is exactly the stack that's being performed.
Data Table( "Table" ) << Stack(
columns( :X1, :Y1, :X2, :Y2 ),
Source Label Column( "Label" ),
Stacked Data Column( "Data" ),
Number of Series( 2 )
);
As for the Graph Builder, rearranging the parameters produces this:
Graph Builder(
Show Control Panel( 0 ),
Variables( X( :Data ), Y( :Data 2 ), Overlay( :Label 2 ) ),
Elements( Points( X, Y), Smoother( X, Y ) )
);
Of course you would have to relabel the "Data" (X1&X2) and "Data2" (Y1&Y2) columns accordingly..
PDB