These napkins are amazing - 12 in count 24.5 x 25.5 - true banquet size.  They are interesting in that a monogram is woven into the damask at the center and there is a two letter, simple, embroidered monogram on one corner.  The fabric is millmarked but I do not know the origin. 

I would date these to the late 1920's / early 1930's based on the art deco influence.  I purchased them in England.  I do not know if they were woven for commercial or residential use.  Somehow, I'm leaning toward commercial.  The linen is very fine and heavy; the woven-in monogram and color indicate a statement was being made; but they are machined hemmed at a time when napkins of that quality in the home would have been hand hemmed.

There are a dozen matching cocktail napkins in a separate listing.