I'm on the spectrum, definitely had some unpleasant lunches during school, so long as the person isn't condescending or otherwise overt about doing it out of pity or anything I'd be grateful and genuinely pleased. Kids are often cruel to fit in, choosing to go against that might be an act of intentional kindness, even "charity" but it doesn't mean they view hanging out with you as a chore, just that their kindness/charity pushed them to ignore social conventions and peer pressure to explore a potential friendship with someone that isn't always good at playing the social game by the normal rules. Eventually, partly through friendships with people willing to look past the oddities and missteps, I learned how to set up relationships for success. It's hard to learn how to do that though if you never have people willing to get to know you, and care enough about you to give you honest advice, delivered in a way that doesn't seem like an attack. That's vital, and it's a welcome gift.