Best Practices for importing / creating activities and campaign follow-ups

Summary:

We are looking for a way to import activities for contacts. Specifically, we went to a go to a trade show and had an dinner event. We come back and we want to:

1. upload an activity to the each of the people who attended the dinner so we have a history that they were there.
2. We also want to create a Task or Campaign Activity or some other recommended object, that can be assigned to a sales Rep to then follow-up on.

How do I setup a n import and have it first run the action. Second is to create the activity/task/campaign response (or whatever is recommended); so we can track the results from the sales contact with the person.