Interesting. I "thumbed" through it, actually scroll wheeled, down quite a way was something I had not thought about in years, but sharp memories quickly returned. Curtain Stretchers! We had a set when I was younger, might still be in the attic, but man were those dangerous. All those nails sticking out, made assembling the thing a literal pain. Plus you had to carefully place the curtains, or tablecloth in place so as not to tear it.
I have a large white hand crocheted table cloth somewhere that we used to stretch on it. Pulled it out 10 or 12 years ago for Christmas and put it over a red tablecloth, looked very festive, but after laundering I did not stretch it...