The other thread people are referring too and pretending it's the same thing is ridiculous, I'll tell you why.
One scenario, a man was contacted by his ex (who he hadn't seen for essentially 20 years or kept in contact with) to go for coffee, and what was interesting was the entire 20yrs with no contact she was married, but suddenly single for the first time, wanted to meet up with her ex for coffee. That is completely different. That's someone the guy has had sex with for years wanting to meet up again, out of the blue.
This?? The restaurant woman and OP are complete strangers. The restaurant woman apparently is prickly with OP. And whilst having no idea that OP is single, the restaurant woman thinks OP is a threat to her marriage, thus explaining the prickliness 
Any attempt of "OP, maybe it's because you're going in there and taking a table for an extended period of time, especially as you're taking a book to read with you, and she'd rather get on with using the table for a couple who will have 3 courses each and a bottle of wine"...is meet with bizarre responses that have little relevance such as "I'm eating the most expensive thing on the menu every time I go in, for nutritional value". And?? It's still not the same as the 6 courses a couple would be ordering.
Yes, it's shitty that she's making her annoyance visible, but: It's. Not. Because. You're. Threatening. Her.
Any pretty obvious suggestion of "maybe she's just an arse, take your money somewhere else where the staff are pleasant". Gets these "internalised misogyny' chirps, which are so out of context, it's pretty apparent OP has found a "buzzword" and doesn't quite know that it means.
Or, OP keep going to the same restaurant, with the same poor service, convinced it's because you're a divorcee, when they have no idea that you are a divorcee. Because if you go somewhere else, the system wins, right 