From lagometer it seems client side ping problem. It might happen due to your wifi or internet sharing or packet loss.
I would suggest to stop all applications that uses the internet, such as Internet browsers, downloads, ICQ, Teamspeak, skype ect. Disable anti virus and firewall while playing ET.
Adjust your maxpackets or rate. Also, try to lower your graphics settings and see how it goes.
For packetloss you can type \showdrop 1 in console and it will show you if you are dropping packets or not.