Large sized...or "Coffee Table" books are not quick sellers...
They tend to be specialized books with lots of pictures...and the content is generally ephemeral.
But certain books are worth having... Books about very high end areas like Martha's Vinyard, or Jackson Hole or Aspen will have a following... Perhaps well off people want these books for their "coffee tables" at condos in the area...
People are not shy about buying large cookbooks... There are several deluxe editions out there that are sort of collectors items...they have a following.
Books on Fung Shei and Japanese Gardens are good bets.
Art Books are a good area IF you know that to buy...
Generally out of print books about blockbuster exhibitions are worthy additions.
Also, art exhibition books for some lesser known artists are often the only resource for that artist's work for years to come...
I would definitely consider picking up "exhibition books" for lesser known artists just on "spec" that they may be more popular in the future... Imagine if you had some early Andy Warhol exhibition materials...!
Generally you don't want the best and most well know artists...they are too popular...and the printings will be huge. I'd rather look into second tier artists...who are still established in their genre...and whose work will be studied in the future.
Some important historically significant, but second tier artists will only have "solo exhibits" at key museums every ten or twenty years... These exhibition catalogs could be money in the bank for the bookseller.
I have stacks of oversized books in my inventory...and they do sell... I order special boxes (12X12 inches) to mail them in. They also usually take a 14 inch mylar DJ cover... Although having a big 16 inch might be needed for huge atlas sized books.
People will "cherry pick" your inventory just as in other kinds of books... It's amazingly how the customers can focus in on the very best books...
They know what they want...and they go for it.
