Hi Tessa T., on the Event Report, filter for IsChild = False. That should clear out all the other records and show only the primary event record.
So, it does create child records for each additional contact you add to the meeting, that way if one person cancels it doesn't cancel the meeting for everyone. Those child records aren't seen in UI, only the parent with the 5 contacts.
The IsChild parameter MAY NOT be accessible in UI so you'd need to create an IsChild__c formula field on the Activity object and reference the standard IsChild function in the formula. Then you could filter the report on the new custom formula field.