You would use one single view model in your form, you would have a post action that receives your single view model.
In your Controller code:
public ActionResult GetSomeData(MyCustomViewModel model){
// add the first element
var person = Person.Add(model.Person);
// update the second object in model, with related / needed ID
model.PersonContent.PersonId = person.id;
// add in related content
var AddedContent = PersonContent.Add(model.PersonContent);
}
single form, multiple actions, multiple tables