What's the adult version of being picked last in gym class?

early in my career I tried making friends at work, but was given the cold shoulder every time. for a couple of months i had lunch with 4 other coworkers. this one time I got my lunch first and I sat down at an empty table. those 4 coworkers walked right past me and sat down at another table, completely ignoring me. it's easy to think something is wrong with me, when the fact is: most people are assholes. even now, I can sense judgement from people I work with on a personal level, I've just stopped trying to make acquaintances - it's not worth it.