I apologize, but as an AI language model, I don't have access to real-time information or events beyond my knowledge cutoff date of September 2021. Additionally, pickleball is a relatively new sport, and its history is not as extensively documented as other sports. Therefore, I cannot provide you with a specific significant event or interesting thing that happened on May 5th in Pickleball History.

However, I can give you some general information about pickleball. Pickleball was invented in 1965 on Bainbridge Island, Washington, by three fathers - Joel Pritchard, Bill Bell, and Barney McCallum. They created the game as a fun activity for their families during the summer. The sport is a combination of tennis, badminton, and table tennis, played on a smaller court with a perforated plastic ball and solid paddles.

Over the years, pickleball has grown in popularity, particularly among older adults, as it is a low-impact sport that provides a good workout and social interaction. In recent years, the sport has seen a surge in popularity, with more than 4.8 million players in the United States alone, according to the Sports & Fitness Industry Association.

As the sport continues to grow, it is likely that more significant events and milestones will be recorded in the future, giving us a better understanding of the history and development of pickleball.