I suspect that the first book of engravings that Carr published contained the work of Thomas Bewick, which may have got him interested in engravers. Bewick illustrated books and designed bookplates, the labels used by owners of books to mark them as ex libris, a neglected art form which Carr also championed. I have a small collection of bookplates which you can find links to from my Home page.
Carr published the work of 11 modern wood engravers, all of whom were paid a modest fee. These 11 books were printed on better paper than the other small books, and with better quality card for the covers. Carr used engravings by some of these artists in the novels he published.
The first number given next to the title below is the number indicated in the History of the QTP (1987); the second number is the number of editions or impressions seen or suspected. If the first number is 0 then it was not listed in the History of the QTP, probably because it was published after 1987.
Each small book is identified by an alphanumeric code: SBE for Small Book, Engravers, followed by the first three letter of the engraver's surname and a number to identify the impression.
Other books of engravings:
The cover of an impression of the engravings of Thomas Bewick