What is your network setup ?
You dont need another router ... what you need is a network switch

So your setup should look like this :

MODEM - ROUTER - NETWORK SWITCH
or
MODEM with built in ROUTER - NETWORK SWITCH , then you can connect anything to the network switch with wired connection.

If you want to connect 7 extra device with wired connection there is a switch for you :
NETGEAR ProSAFE 8-Port Gigabit Ethernet Switch (GS108) - Lifetime Warranty

If you want to connect 4 extra devices with wired connection there is a switch for you :
NETGEAR ProSAFE 5-Port Gigabit Ethernet Switch (GS105 v5) - Lifetime Warranty