Little House on the Prairie - Season 8 Episode 14 -

A present-day couple buy an antique, folding-leaf table with a large "I" branded on it and are curious to learn about its origins. The story focuses on Charles' efforts to patent the table and have it mass produced. However, a ruthless businessman is successful in a bid to steal the patent and snare an ill-gotten profit, forcing Charles to realize that his family, and not the tables, are his greatest legacy.