I also find blowing noses at the dinner table to be vulgar. Same with picking your nose, digging in your ear, farting, wearing a half gallon of cologne, perfume, or crying babies, or kids bouncing on the seat behind me (since usually the booth seats are attached).
All the things listed I do not like. But, I’m not going out of my way to chastise someone on it. These are also things I don’t do at the table when eating in or out.
(Except blow my nose at home. I don’t find it vulgar. Just something to avoid if possible. Rude? Yea. Vulgar? No.)