The Royal Collection Trust saw retail sales jump more than 20% to a record £19 million last year, its annual report showed.
Sales of the Queen's official 90th birthday commemorative china helped boost the figures, as did a soaring trade in ice creams.
Ice cream consumption jumped by 300% because of new sale points at Buckingham Palace and Windsor Castle, which proved "hugely popular" with visitors during the summer months, the report revealed.
Other ranges included a new pet accessories collection, featuring leather dog leads and collars.
The drop in the value of sterling last year also increased the spending power of overseas visitors, the report said.
Spend per visitor increased by 13% in shops, while the total retail sales in shops and online came to £19,034,000 in 2016/2017, compared with £15,845,000 in 2015/2016 - a rise of around 20.1%.
The report said royal events and anniversaries "drove the most successful retail performance to date, with record sales on site and through the online shop".
The trust maintains and displays the large collection of royal artefacts from artwork to furniture held in trust by the Queen for her heirs and the nation. It also carries out other charitable work.
Visitors numbers were up on last year, with a total of 2,723,000 tourists visiting Buckingham Palace, Windsor Castle and Frogmore House, the Queen's Gallery London, the Royal Mews, Clarence House, the Palace of Holyroodhouse and the Queen's Gallery Edinburgh - a jump of 167,000 from the previous year.
Total admissions income, including Gift Aid, came to just over £39.5 million, up more than £5 million compared with the previous 12 months.