According to background material created for Star Trek Generations, The Silver Spade is an award given to winners of bridge tournaments by the Federation.

On stardate 34180.7, Starfleet held a tournament on Risa. The winner was Jean-Luc Picard, who was awarded the Silver Spade.

The article containing this information was included in the Picard family album during the filming of Generations. However, the information is non-canon as the article was never seen on-screen.