The reason it displays empty cells, is because it is a view into an existing data table. Here is another script that just adds a visual copy. The script has to be a little tricky in it's method to place the data table view under the outline box.
Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/big class.jmp" );
nw = New Window( "sample journal",
<<journal,
ob = Outline Box( "Selection 1",
Text Box( "this is some description", Markup( 1 ) ),
hlb = H List Box()
)
);
xx = New Window( "xxx", <<journal );
dt << journal;
hlb << append( xx );
xx << close window;
Jim