This bit of code will do it, but is there a more elegant solution? It makes the header dissapear only on the last table in the journal.
current data table() << journal;
current data table() << journal;
current data table() << journal;
TableNumber = n items(Current Journal() <<xpath("//TableBox"));
boxes = Current Journal()[TableBox(TableNumber)] <<xpath("//StringColBox");
For(i=1, i<= nitems(boxes), i++,
boxes[i] << set heading("")
);
boxes = Current Journal()[TableBox(TableNumber)] <<xpath("//NumberColBox");
For(i=1, i<= nitems(boxes), i++,
boxes[i] << set heading("")
);