The most common and most likely answer to this crossword clue is the 7 letter word CUTLERY
I've seen this crossword clue in The Daily Telegraph
C
U
T
L
E
R
Y
Buddy explains!
The straight part
We know that "it’s usual to dine with them" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case it’s usual to dine with them = cutlery.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CUTLERY mean?
CUTLERY noun- A collective ensemble of eating and serving utensils such as knives, forks and spoons.
- The business of a cutler.