The 32-year-old said the record was loosely inspired by Edward Elgar, whose 1899 Enigma Variations also featured 14 sketches of his wife, friends and colleagues.
It received mixed reviews – both tricks and treats, to continue the October theme – on its release last week.
The Guardian's Rachel Aroesti gave the album two-stars, saying it was – "as flat and dull as a grey sky".
"Plodding, genre-hopping songs all end up as unimaginative ballads, their dreary lyrics littered with gibberish – though Sheeran's hooks remain strong," she wrote.
NME's Thomas Smith agreed, also offering two-stars for "a pumpkin-spiced snoozer".
"Four months after the soul-baring Subtract, Sheeran returns with a cloying, seasonal-themed endeavour," he said.
Three stars were dished out by The Independent's Helen Brown, who said: "There's no standout tune on here to match Elgar's Nimrod, of course, but there's enough soupy seasonal sentimentality to fill the Royal Albert Hall."
The Times' Will Hodgkinson was more generous, however, awarding four stars while saying Sheeran "has a way of taking mundane aspects of life and imbuing them with real feeling within a melody that sticks in the mind." He added: "For all his apparent normality, that really is a rare skill".
Sheeran has shrugged off critics, telling Rolling Stone magazine their opinions are redundant in the streaming era.
"Why do you need to read a review? Listen to it. It's freely available!" he said.
"Make up your own mind. I would never read an album review and go, 'I'm not gonna listen to that now.'"
Instead, he said it had been "amazing to get reconnected with the fans" over the summer, and promised a follow-up album next year.
One fan, Kari, was even treated to a surprise home visit from the star who performed the album's lead single American Town for her and her friend in her living room.
Video of the stunt was shared on social media during the week. (BBC)