A. RECENT facetious comment by the ' Broadcasters ' on the folding of table napkins to. look like water-lilies brought those embarrassed gentlemen scores of letters explaining how the thing was done-and even some water-lily napkins themselves neatly folded in cardboard boxes. The interest in this piece of old table etiquette is therefore obvious. This week, Mrs. Stephonson will explain the diamond fold and the fan fold.