I have cable internet connection and cable connects to modem. From modem there is a LAN cable connecting to my laptop. Can electric surge reach my laptop?
Depending on the design, it is highly likely it could take out the modem card rather than the entire machine, but it is still possible and depends entirely on the design of the laptop.
Electricity can run through any cable and fry what is attached.
I had one client who ran indoor grade cable to join buildings together - it got struck by lightning and took out EVERY network port, router and other equipment on the network! Thankfully for most computers, all it took was a cheap network card to fix!