Routes are not defined for a NIC but for a destonatin network.
Thus you can have multiple routing table entries for diffrent networks.

i.,e. on my machine , I have a default route goes through my frontend network. And then a summary route for one of the Class C network which gets me to the NAS and other devices. and then some other routes for the management networks. I have 3 ethernet cards with diffrent ip address in them.

Regds,

Kaps