When families gather for Christmas dinner, some will stick to formal traditions dating back to Grandma's generation. Their tables will be set with the good dishes and silver, and the dress code will be Sunday-best. But in many other homes, this china-and-silver elegance has given way to a stoneware-and-stainless in formality, with dresses assumig an equally casual-Friday look. For hosts and guests, the change means greater simplicity and comfort. For makers of fine china in Britain, it spells economic hard times. Last week Royal Doulton, the largest employer in Stoke-on-Trent, announced that it is 'eliminating 1,000 jobs--one-fifth of its total workforce. That brings to more than 4,000 the number of positions lost in 18 months in the pottery region. Wedgwood and other pottery factories made cuts earlier. Although a strong pound and weak markets in Asia play a role in the downsizing, the layoffs in Stoke have their roots in earthshaking social shifts. A spokesman for Royal Doulton admitted that the company 'has been somewhat slow in catching up with the trend' toward casual dining. Families eat together less often, he explained, and more people eat alone, either because they are single or they eat in front of television. Even dinner parties, if they happen at all, have gone casual. In a time of long work hours and demanding family schedules, busy hosts insist, rightly, that it' s better to share a takeout pizza on paper plates in the family room than to wait for the perfect moment or a 'real' dinner party. Too often, the perfect moment new ex comes. Iron a fine-patterned tablecloth? Forget it. Polish the silver? Who has time? Yet the loss of formality has its down side. The fine points of etiquette that children might once have learned at the table by observation or instruction from parents and grandparents (' Chew with your mouth dosed.' 'Keep your elbows off the table.') must be picked up elsewhere. Some companies now offer etiquette seminars for employees who may be competent professionally but clueless socially. The trend toward casual dining has resulted in ______