The Auto Join Tables option automatically joins database tables as they are added to the Content frame using one of three different join strategies. If Auto Join Tables is not selected, you can manually create joins between topics in the Content frame.
To automatically join topics as they are added to the Content frame:
Select the Auto Join Tables check box and then click OK.
When you add tables from the Table catalog to the Content frame, joins automatically display between topics.
Clear the Auto Join Tables check box to turn off this feature and manually create joins yourself.