Santa Claus melon (a.k.a. Christmas melon) is a type of melon with an excellent shelf life. Hence its winter name (i.e. “until Christmas”), despite the fact it is a summer fruit.
As with most fruits, melon is an excellent source of vitamin C and fiber. The fiber is good news because melon is also pretty high in sugar. The fiber helps slow down the digestion of that sugar so it doesn’t cause a massive spike in blood sugar. We tend to want to avoid spikes in blood sugar, because a spike leads to a crash, leaving us feeling tired, cranky, and craving more carbs to get our blood sugar back up.
That said, some people need a little more carbs in their diet, and melon can be a perfectly Paleo-friendly way to get those carbs in.
Mark Sisson mentioned melons in his list of best and worst fruits for those trying to restrict their carbohydrates.