Real World article(written from a Production point of view)
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.