New Zealand! You live in paradise! Porch paint is specially made paint for wooden porches or decks. Its not a stain but an actual hard wearing & weather resistant paint that allows the wood texture to show through. Its safe for indoor or outdoor use. It is self priming & self sealing. I have used porch paint for wood paneling & kitchen cabinets & when remodeling a staircase formerly covered with carpet. It comes oil based or water based acrylic. I prefer oil based for a glossy easy to clean finish for a wooden table top. You may check your local home improvement/hardware store or paint store. I use Glidden Porch Paint. Takes me only 2 coats for white & the oil based goes on easily with a roller. Dries quickly too. Good luck!

Thanks for responding. We're in Auckland, New Zealand and close to the sea. Outdoor living is quite important but it does get chilly in winter so it's a balance. There are three adults and two young children in the household (one of the adults is an Au Pair who likes to spend time in her own room in the evenings). The kids will watch their cartoons generally in the morning and a bit before dinner. Then in the evening my husband and I will relax and watch TV. Right now the kids' toys are in the family room downstairs. We are foodies and like cooking. Generally when guests come over we all hang out in our small kitchen at the moment. The dining table we use for every meal time. We also like the idea of being able to get to the deck from the kitchen, rather than having to carry food in summer through the lounge/dining. The entry way is that big in order to reduce on the structural work but also in order to ensure that the door to the staircase is not in the lounge.

You can of course have a furniture repair business add material and refinish. Or you can add a center accent piece of tile, or wood inlay. If you're going from a narrow rectangle to a square, you would need to disassemble the table anyway, might as well do something fun with it.

If it is a casual buffet type meal you don't need to go over board on the dinner table. I would suggest a lovely table runner a pose of fresh flowers (not high so that you block peoples view across the table). Some lovely place mats, standard silverware and glasses all set out and a couple of very simple candle sticks - I also love the idea of the mini Led Fairy lights but maybe around the room (perhaps a mirror if you have one in the room). If you have napkin rings or can make lovely napkins shapes out of origami, that adds a little bit of class and perhaps a small chocolate at each place setting. Don't go over board. After all it is the company (and the food) that should be the star of the night and you need to relax as well. Not every decorative piece needs to be on the table.