I don't use facebook so I'm not familiar with their app ecosystem. But my first thought is that some app on 192.168.1.102 is in a phone-home-frenzy. The app might be bugged; the name of that facebook subdomain[?], "0-undefined..." doesn't look right. Some programmer likely dropped the ball and the app isn't correctly loading whatever name that should be. Since the app can't phone home, its probably, annoyingly, programmed to keep trying until the server responds.
Actually, that was my second thought. My first thought was that this isn't a pihole problem. Its a pihole benefit. Your pihole discovered a problem on your network of which you took immediate notice. Check out these these pihole posts for many many eyepopping stories where a pihole discovered Gadgets Gone Wild. Its definitely a benefit.
So like I said, I don't know squat about facebook. Check around on 192.168.1.102 for facebook related apps and shut them down as a test. I think that's the problem there. Also it might be worth looking into whether other people are having this problem with 0-undefined.facebook. com.