@mutebnaser, you cannot transfer 240 Mbps full-duplex over a N300 half-duplex wireless link.
The CPE510 has a 100 Mbps full-duplex LAN interface. Full-duplex means it provides 100 Mbps throughput in each direction (that's 100 Mbps for sending and 100 Mbps for receiving) at the same time, thus yielding a total of 2x 100 Mbps = 200 Mbps.
WiFi is half-duplex. A N300 AP such as CPE510 with a theoretical wireless throughput of 300 Mbps can achieve a practical data throughput of ~210 Mbps (at ~30% protocol overhead in n-mode). The 210 Mbps are for either sending or receiving, but not at the same time. Since sending data over TCP/IP requires receiving an acknowledgement for each packet sent, the CPE's 210 Mbps data throughput in half-duplex mode matches the data throughput of a 100 Mbps LAN in full-duplex mode.
The effect is that wireless throughput of a N300 AP limits LAN throughput to 100 Mbps anyway, no matter whether you use a 100 Mbps or a 1,000 Mbps LAN interface.