Was Sein Dies?

A few months ago Dad asked for help re-organizing his linen closet. While going through the items we found some lovely treasures, antique lace tablecloths with matching napkins and such. There were also a number of unmatched sets of dinner or luncheon napkins, doilies and table runners, and some mystery objects.
I found these two hand embroidered, counted cross stitch envelopes. I do not ever remember seeing these little envelopes before, nor does my Dad. The envelopes bear my great- grandparents' initials. My great-grandparents came to America from Germany just over 100 years ago. I think these must have has some special significance, or Mom would not have kept them. A few weeks ago, I saw something similar on Mumintroll's blog, but I was unable to comprehend the details in German about her photo.

I admire the picot edged ribbon stitched to the outside edges of the fabric. I would love to know what these are called! Are they Christmas items? And what was their purpose? I'd like to tell my children about them.