Currently, Scheduled Reports do not have an option to automatically suppress the email when the report returns no records. The report will continue to send according to its configured schedule, even when there is no data.
If emails should only be sent when the report contains records, use a Scheduled Email Merge instead. Scheduled Email Merge will not send an email when the underlying report returns no records.
When configuring scheduled reporting, consider:
Scheduled Report: Sends according to the configured schedule, even when no records are returned.
Scheduled Email Merge: Sends only when the underlying report contains records.
For scenarios where empty report emails should be avoided, Scheduled Email Merge is the recommended approach.