jonw:
One of my earlier designs had exactly what you are talking about. A pass through, that would allow cooking (or better yet that first pot of coffee in the morning) from inside if necessary.
One other thought I had with my current design, is the ease of placing a canopy.Having a side mounted table (or the slide out) means I only need to put an awning up on one side of the trailer. A rear hatch configuration would mean two awnings, or dual purpose awning (part over hatch, part over entrance) and much of the awning would be over the trailer. That's a wast of the awning space in my opinion.