According to Official Guinness Records,
The most eggs carried on a single hat is 735 and was achieved by Gregory Da Silva (Benin) on the set of CCTV - Guinness World Records Special in Jiangyin, Jiangsu, China on 12 January 2015. Gregory spent 3 days attaching the eggs to his hat for this attempt.
For a complete list of 2015 records, please visit 2015 Guinness Records in China.