Complex sentence: He was subsequently selected to provide the picnic meal for participants in Queen's Diamond Jubilee celebrations, and was a guest in the Royal Box at the Queen's Diamond Jubilee concert in June 2012.
Split into simpler sentences: He was subsequently selected to provide the picnic meal for participants in Queen's Diamond Jubilee celebrations. In recognition, he was a guest in the Royal Box at the Queen's Diamond Jubilee concert in June 2012.