According to Official Guinness Records,
The largest cream tea party consists of 978 people and was achieved by Cath Kidston Ltd. (UK) at Alexandra Palace, in London, UK, on 1 July 2018.The attempt took place to celebrate Cath Kidston's 25th anniversary and was attended by fans of the brand including Mary Berry. The team behind the event donated 100% of the ticket sales, £11,000, to their chosen charity, Friends of the Elderly.
For a complete list of 2018 records, please visit 2018 Guinness Records in United Kingdom.