If you have a simple wire photo holder like this one, you can display the leaves instead of photos.
Choose a tall, thin pumpkin with a steady base. Carve and empty it as usual. Find a glass or vase that fits inside it comfortably. Put water in the glass or vase.
Cut cardstock or cardboard to fit inside the frames. Decorate with a few small leaves. Write or stamp the names of your guests on the cardstock.
Many local grocery stores print fall or harvest messages on their bags at this time of year. Just cut out the sides to make a place mat. Decorate by gluing leaves in the corners or at one end.