Autism aside, no one wants ‘accidental spit’ in their food.

Thanks for the vindication.

It very possible to have some drops projectile forwards when talking in between eating or otherwise even if you have a habit of chewing with an open mouth.
I am aware of this and tend to keep my head in a direction that doesn't cause the spit to go in the other's food and if not, I cover my face while talking.

There are people who will force a chat while eating and of course their spit will drop into my food, after which they will confidently state that they haven't.
This was mostly in the school time. Nowadays, I don't bother pointing out such people and just stop interacting with them instead.

But either way, it is good to have some space while eating. Specially in the front.
So when going out to eat with someone, I try and get a 4-table and sit diagonally.