The rate of heat transfer from material K is much faster than material L as the wax melted faster when heating up material K. In another words, you feel the rod heated up faster when holding material K. To cook with the pan, heat must be transferred faster in the pan so that your food gets cooked faster. While the heat transfer in the handle should be slow, so that you can hold the pan at the handle when cooking. Look up more for Heat Conduction chapter.