The episode is "Sirens" (episode 11 of Joyce's Ulysses, 1904)
After Leopold Bloom has had his dinner in Ormond Hotel and has completed his pseudonymous love letter to "Martha", he wants to pay and leave, to dispatch the letter. Bald Pat, the waiter, who is deaf, does not hear his call at first, however:
What exactly is Pat occupied in?Pat! Doesn't hear. Deaf beetle he is[...] Pat! Doesn't. Settling those napkins. Lot of ground he must cover in the day. Paint face behind on him then he'd be two. Wish they'd sing more. Keep my mind off.
Bald Pat who is bothered mitred the napkins. Pat is a waiter hard of his hearing. Pat is a waiter who waits while you wait. Hee hee hee hee.
There is a verb "to mitre", meaning "raise somebody to a bishop's function" (i.e., pass the mitre on to him), which cannot be meant here.
There is also a second verb "to mitre (~miter)", applied to a technical procedure where one folds in two some material having a right angle with the fold ending in the corner, whereby two parts ending in an angle of 45° each are produced.
Can THAT be meant here?