Look around your house and see what display pieces you already have that might fit with your design. You can fill wooden bowls with pinecones and include some wicker baskets overflowing with fresh fall produce. A quick trip to the pumpkin patch will yield mini pumpkins to hollow out and use as candleholders or to hold place cards at each setting. Instead of a fabric table runner, use a moss mat. Make a string of berries using a needle and thread, and weave it throughout the table settings or hang from the chandelier. The materials are endless, so all you need to do is rev up your creative juices and imagine the possibilities.
You can actually do this. All you need to get started is a moss starter (kind of like sourdough bread) and a blender. Blend the moss with a cup of yogurt or a cup of buttermilk and then spread the mixture over the area you want it to grow. Outdoor shady areas are best, and it needs some regular misting.