1. Add a checkbox field to your Table A. This checkbox will indicate whether there are related records in Table B
2. Add triggered actions on Table B's insert, update, and delete events. These triggered actions will check or uncheck a checkbox on a related Table A record based on your specified condition.
3. Add an application task that will run once a day to loop through all records in Table A and check if they have related records in Table B with a date after today.
4. Build a view based on Table A to filter out records based on the checkbox.
5. Build report DataPage based on this view
Volomeister's post in I need a tabular report DataPage that shows all records from table A that DON'T have a corresponding record in TableB with a date after today. was marked as the answer