Nope, unfortunately not. Though if you’re wanting to block someone because they’re making personal attacks, not contributing anything of substance, or being continually disrespectful then you can report them. In my experience the people who are problematic enough for me to want to block end up getting banned eventually anyway.
If it’s just a matter of not agreeing with what they say or thinking they’re annoying then you just have to do your best to ignore it. It’s a good skill to practice I suppose since you can’t block people in real life, either!