I had a blood test done, what does it mean? Kappa monoclonal gammopathy. Is this rare? Does this mean cancer? Is this anything to worry about?

Not necessarily. You don't tell me why the test was done in the first place. Kappa chain is one of 2 light protein chains that are part molecule of an immunoglobulin. In your case, it is half of an igg. Even if you are asymptomatic, you may develop a problem over 20 years. If you have symptoms, you need further evaluation. If there is no specialist where you live, go to the university of washington in seattle.
If . If you don't already have an appointment with the doctor who ordered these blood tests you should make one to go over the results. Hopefully you have what is called monoclonal gammopathy of unknown significance (mgus). This is a fairly common precancerous condition. It has a low risk of about 1% per year of turning into a cancerous condition called multiple myeloma or a related plasma cell tumor. Additional tests might be needed to determine if this is the condition you have or if the disease is more advanced.