How I think each race would react to finding an abandoned baby on the side of the road.

These answers do not account for individuals and goes off of the general characteristics and personalities of each race in the games. It's very well possible that an altmer or a dunmer would willing adopt a baby of a different race or for an argonian or nord to eat a baby they find.

I feel like the average altmer would ignore it. Or at most drop it off at an orphanage.

Argonians are probably the most compassionate races out there because we have an actual in universe of something like this happening and argonians being more than happy with raising an orphaned child, and a dunmer no less.

Bosmer would at best, take it to an orphanage and at worse eat it.

For Bretons it depends because if they're in highrock they'd probably ignore them but if they live abroad I feel like they'd feel more inclined to help the child at the very least.

Dunmer would most certainly leave them. Exceptions made for a dunmer baby but it depends if the baby was originally born in morrowind and if they know that it was.

Imperials would probably be similar to Bretons. Maybe a little more compassionate.

For nords I'm convinced they'd just dump the child at an orphanage with rare exceptions. I mean, whenever a kid's parents die they just get shipped off to the riften orphanage.

Orsimer: probably up to the individual, I wouldn't really expect a stronghold Orc to willingly take in a random baby the found. Probably leave it at the front gate of the nearest city.

Redguards: potentially similar to Bretons and Imperials. Haven't really seen them enough in the games I've played to draw a solid opinion.

Khajiit: the stereotypical thing to answer with would be "oh they'd sell it for skooma". But in actuality I think the khajiit would be generally very compassionate towards a baby. They just give off that vibe when they aren't characterized as criminals or drug addicts.