The Thanksgiving Festival in Korea is called 'Chu Suk' which was known as Hangawi(Harvest Moon Festival) is a major harvest festival celebration celebrated on the 15th day of the 8th month of the Lunar Calendar. It is celebration which stretches for 3 days and those 3 days are public holidays in Korea.
A Jesasang or a ceremonial table will be prepared on Chu Suk.
It is a feasting time and also time for happiness for Koreans. Food such as Songp'yon(crescent-shaped rice cakes stuffed with sesame seeds, chestnut paste or beans, are a Chu Suk favorite) and also Taro Soup.
Finally, Koreans celebrate by having singing competitions, archery and wrestle to mark the festival and show gratitude to their God.
Source: www.thanksgiving-day.org/celebration-korea.html , www.wikipedia.org
Credits: White-Kiss