In honor of the US holiday today...
Oliven gibt es in vielen amerikanische Haushalten nur einmal im Jahr, als Bestandteil der Truthahnfüllung. Die Kinder sind fasziniert und spielen damit rum.
I have neither ever eaten nor heard of olives being put in the stuffing for the turkey. I suppose some people somewhere might do so, but it is by no means common.
As Carly-AE wrote, we, too, had olives at holiday meals when I was growing up. My mom or my aunts, whoever was hosting the meal, would create a carefully planned relish tray that consisted of green and black pitted olives (perhaps stuffed with pimiento if green), glaring green and/or red pickled crab-apples, and a few other such treats.
My cousin, who was my age, and I definitely put the olives on our fingers during the meal -- it worked better with the unstuffed blacked ones. Our folks weren't especially thrilled by it, but they knew that we'd eat the olives afterwards so that they didn't go to waste.
Oddly enough, an anti-war protest song sung by Arlo Guthrie in 1967 established itself as a sort of Thanksgiving tradition over the years as radio stations around the country played it on Thanksgiving, often by listener request. (It apparently began as part of a fundraising campaign at a publicly funded station in New York City and spread from there.)
If you have 18.5 minutes to listen, here is Mr. Guthrie singing it:
https://www.youtube.com/watch?v=WaKIX6oaSLs&t=6s
