I agree with the previous post. The growling is not bad behaviour, it is the dog communicating with you to saying please get out of my personal space, I don't like it while I'm eating. The dogs next reaction is to take the only further step he can do, which is to snap or bite.
I too have a springer that is totally gentle and laid back, but many cockers often have a much more sensitive temperament. Mine is well documented on the forum seven years ago as a difficult puppy. We learnt to understand his signals and 'think like a dog' and use positive training methods.
I would advise you to read up the recommended dog behaviour guides so that you are prepared for any other possible problems like guarding and jealousy so that you know what to do. I never had to think about positive training methods till I had my cocker! Also, Clicker training is brilliant, and such good fun for all the family. Are you going to training classes with him?