During data import, there are some object export that are related to another object. The object relationship is only referenced using ID, hence, it’s impossible to identify the object type that it’s related to.
Here we would like to share the parameter you should use to know the object type that is related to Task. The following is a data export of task record.
To get the associated object:
From the above, you will see the event is related to the contact and case object.