How do I tell my partner their jokes about my job land badly What Do I Say

In private, at a neutral time, and about the pattern rather than any single joke. "When we're with people the spreadsheet thing comes up a lot and it's started landing badly for me" is one sentence and it doesn't require them to have done anything malicious.

Then say what you want instead, because "stop" leaves a hole. "I'd rather you skipped the work jokes in group settings, they're fine one to one" gives them somewhere to put it.

The keeping-score worry cuts the other way, by the way. A year of silence is exactly why saying it now, calmly, is easier than saying it after the next one at a dinner table.

Lead with the fact that you know they don't mean it badly. Not as a softener you don't believe, but because it's probably true and it keeps the conversation about effect rather than intent. Arguments about intent are unwinnable and beside the point.

One thing to check honestly with yourself first. Is it the joke, or is it that you're not sure how they actually see your work? Those need different conversations, and the second one won't be fixed by them dropping the bit.

Tactically: don't do it in the car on the way home from the event. Everyone's tired and it reads as a reaction to that specific evening rather than something you've thought about for a year.