At this time, users are unable to delete individual events from the platform. However, there are a couple of strategies you can use to delete events.
Strategy 1: Use a "deleted" tag & filter your data
Add a "deleted" tag to your events and set it to true for the events you would like to delete. The events will still be on the platform, but in Workflows and on the User Portal, you can filter the data to only show events where "deleted" = true.
Strategy 2: Store events in a stream for a limited time
On the M1 platform, go to Config > Data Streams.
Select a stream.
Under "Days to store events", uncheck "Never Expire" and set the number of days you'd like to store events in this stream.
Note: Events are deleted on a weekly basis, so your data may not be deleted exactly X days after it was created. Events will be stored for at least X days and at most X + 6 days.