1) without using wireshark to determine the traffic, do you think it looks like normal broadcast traffic?
2) is there an easy to way to continue blocking the traffic but now have it fill up the logs?
1. Yes, it looks like normal UDP broadcast traffic.
2. You can disable the "Log all blocked" option in the Activity log, but it's going to stop logging all blocked traffic. There isn't a way to continue blocking it and keep this specific traffic from being logged.