In an InfoPath event the user may have several options in the form to select. Depending on his selection, the outcomes of the event may be defined.
In the event properties we can select, which field in the form should be the task action field:
In the same properties we can define the actions:
In the properties of this field in InfoPath (the control on the form) we can define, from where the available options should come:
Content of the Entries field: