Man pages matching name ip-ntable in section 8:

ip-ntable.8.en	debian 10 / iproute2
ip-ntable.8.en	debian 11 / iproute2
ip-ntable.8.en	debian 12 / iproute2
ip-ntable.8.en	debian 13 / iproute2
ip-ntable.8.de	debian 13 / manpages-de
ip-ntable.8.fr	debian 13 / manpages-fr
ip-ntable.8.ro	debian 13 / manpages-ro