From the Wikipedia page 
The Dispilio Tablet (also known as the Dispilio Scripture or the Dispilio Disk) is a wooden tablet bearing inscribed markings (charagmata), unearthed during George Hourmouziadis's  excavations of Dispilio  in Greece and carbon 14-dated to about 7300 BP (5260 BC). It was discovered in 1993 in a Neolithic lakeshore settlement that occupied an artificial island near the modern village of Dispilio on Lake Kastoria in Kastoria Prefecture, Greece.
The lake settlement itself was discovered during the dry winter of 1932, which lowered the lake level and revealed traces of the settlement. A preliminary survey was made in 1935 by Antonios Keramopoulos. Excavations began in 1992, led by George Hourmouziadis, professor of prehistoric archaeology at the Aristotle University of Thessaloniki. The site appears to have been occupied over a long period, from the final stages of the Middle Neolithic (5600-5000 BC) to the Final Neolithic (3000 BC). A number of items were found, including ceramics, wooden structural elements and the remains of wooden walkways, seeds, bones, figurines, personal ornaments, flutes— one, dated to the sixth millennium BC, is the oldest ever found in Europe, and one of the most significant findings, the inscribed tablet.
The tablet's discovery was announced at a symposium in February 1994 at the University of Thessaloniki. The site's paleoenvironment, botany, fishing techniques, tools and ceramics were published informally in the June 2000 issue of Επτάκυκλος, a Greek archaeology magazine and by Hourmouziadis in 2002.
The tablet itself was partially damaged when it was exposed to the oxygen-rich environment outside of the mud and water in which it was immersed for a long period of time, and it is now under conservation. The full academic publication of the tablet apparently awaits the completion of conservation work.
An article on its decipherment here .