Click the triangular grip at the bottom
center gridline of the table.
When the triangle is pointed down, then
table breaking is inactive. New rows will be added to the bottom
of the table.
When the triangle is pointed up, then
table breaking is active. The current position of the bottom of
the table is the maximum height of the table. Any new rows will
be added to a second table part to the right of the master table
part.