Hosting and Domain panel(Given by registrar like Godaddy) both can create subdomains. Again I want to say that, to create any custom subdomain on blogspot blog you don’t require hosting at all. You just need to buy a domain name.
When you see www on any blogspot blog(like www.example.com) then www is also consider as subdomain. So if you want to create contact.example.com, then you need to add contact as CNAME in your domain panel.
Domain registrar such as Godaddy allowed to create 100 Records, it means you can make 90+ subdomain if you want.(Other records might used in verification or to setup mail server)
And can you please edit your previous reply, please add example.com instead of my site name, thanks