Looks like a common silver plate spoon from the first part of the 20th century. Most likely lost on a picnic outing some time in the past. It should have a makers stamp on the back side of the handle. Most I pick up do as I'm always checking for sterling spoons & forks to buy at a bargain.
Rogers company or Rogers and brothers (there's a bunch of names) made a lot of silver plate spoons back then. I found a few last week, name may be on the back? Rogers: American silver and silverplate manufacturers