Top client list one uber high requests

I have one client on my top client list that is (seems) Extremely high.... it's named as localhost and has over 20,000 (yes twenty thousand) requests today alone.

Is this normal?
Local host is what exactly? I know it's the local loopback lookup (is that right? Not really sure what it means though?)

Localhost means "the computer you're working on." (or "home") it maybe your router or your pi.

Yes

Sometimes router sends queries to NTP server (used to keep time), if you see something like 1.asia.pool.ntp.org or similar, it's harmless

Ah ok, so there's no real way to know whether it's referring g to my Pi or router?
There are zero NTP entries in the queries list for localhost, but a lot for home assistant? 11,000+ to https://home-assistant.io which I also find strange as I haven't navigated to that site today?
Home assistant is installed on my Pi though?

Well, that IoT device is homesick. You may test it by blocking that domain, if it disrupt the functions, you can remove it from the blacklist.