You can block a site by modifying the
C:\Windows\system32\drivers\etc\hosts file; however, it won't just block one single page, it'll block the entire domain.
basically, it's used to override DNS lookups in resolving IP addresses.
If you put 127.0.0.1 as the IP for a domain (i.e. yourself), it's not going to find what it's looking for.
eg adding
127.0.0.1 Welcome to Facebook | Facebook will block facebook
For blocking a specific page or subdomain, I tend to use Firefox + Adblock Plus. I don't know if any equivalents for Chrome have been developed.