It doesn't make sense to cordon off the dining room until a special occasion arises. Nor does it make sense to keep stuffing the room with unpaid bills, opened mail, book bags, last month's school project, and a season's accumulation of dry cleaning. What the room needs more than anything else is a balanced diet of form and function so you can make the most of the versatility it offers, all day long. Capitalizing on classic dining-room elements — overhead lighting, a large table — Real Simple transformed a Delaware family's catchall nook into the perfect place to eat as well as to create. Now feast your eyes....