Linked/Filtered Tables in a Report

Hello, new user with a basic (i think) question.  I have 2 tables in a report - Table A with summary data, Table B with detailed data - both tables are using the same data source (a single table).  When clicking on a record in Table A, Table B filters to just the detailed data related to the record identified in Table A.  When un-selecting the record in Table A, Table B shows all records again.

my quesiton - is there a way to control Table B so that it only shows data when a record is selected in Table A?  I would like Table B to be blank (show no data) when a record is not selected in Table A.

Thanks in advance!

Baroo