Are you kidding? I have 10 coils of electrical wire like that in my small cabinet under my 40g cube. The coiled up wire shouldn't be a problem. I even labeled my power supplies, controllers and even the coils of wire so I know what I'm working with when I have to change or clean something.
Just be sure not to overload any one circuit breaker by plugging in too many things. I added 2 new outlets on 2 new breakers so I could keep the load spread around.