What does “turn down an empty plate” mean?

Question

I was reading Raymond Chandler’s The Lady in the Lake (1943) and came across this quote that puzzled me:

Tell Webber I was asking for him. Next time he buys a hamburger, tell him to turn down an empty plate for me.

What does it mean?

Answer 1

The words are meant literally - "place an empty plate face down on the table next to him". However, this is not a standard idiomatic phrase and is not attested apart from this story, so its meaning here requires some explanation.

Among soldiers, policemen, firemen, and similar professions, it is the tradition when drinking at a bar to place an empty glass face-down on the bar in memory of a fallen comrade, followed by a drink to "Absent Friends". In the passage, Degarmo is implying, if we take his words at face value:

• Webber is such a paragon of virtue that he doesn't drink in bars, so, if he were to perform this ceremony, it would be while eating in a restaurant. This is not the usual way of remembering a fallen comrade, so there's an element of humor in the image (perhaps also making a comment about Webber's weight, although I don't know whether this is part of the novel).
• Degarmo's fall from grace, as a result of Shorty's report, would be so complete as to make his comrades treat him as if he were dead.
• Webber and Degarmo are good friends. This is the only unironic element of the passage.

However, Degarmo's meaning is the opposite of this:

• Webber is just as corrupt as Degarmo.
• Degarmo will not face any consequences, even if Shorty does make an official report.
• As Webber and Degarmo are friends, any attempt by Shorty to set back Degarmo's career will not go well for Shorty.

It's not exactly a threat, but Degarmo is warning Shorty that submitting a report will not have the consequences he hopes for.

EDIT

Here's the full passage for context. Degarmo and Shorty are two police officers, interrogating a suspect. Webber is their chief.

"We'll help you to remember," Degarmo said. "We'll take you up back in the hills a few miles where you can be quiet and look at the stars and remember. You'll remember all right."

Shorty said: "That ain't no way to talk, lieutenant. Why don't we just go back to the Hall and play this the way it says in the rule book?"

"To hell with the rule book," Degarmo said. "I like this guy. I want to have one long sweet talk with him. He just needs a little coaxing, Shorty. He's just bashful."

"I don't want any part of it," Shorty said.

"What do you want to do, Shorty?"

"I want to go back to the Hall."

"Nobody's stopping you, kid. You want to walk?"

Shorty was silent for a moment. "That's right," he said at last, quietly. "I want to walk." He opened the car door and stepped out on to the curbing. "And I guess you know I have to report all this, lieutenant."

"Right," Degarmo said. "Tell Webber I was asking for him. Next time he buys a hamburger, tell him to turn down an empty plate for me."

Answer 2

The phrase "turn down an empty plate" is not a common idiom or phrase in English, so it's likely that Raymond Chandler was using it in a specific context or as a form of character-specific slang in "The Lady in the Lake".

Given the context of the novel and the time period it was written in, it could be a way of saying "remember me" or "think of me". The act of turning down an empty plate could symbolize setting a place at the table for someone who isn't there, as a way of acknowledging their absence.

However, without more context from the novel, it's hard to say definitively what this phrase means. It might be a good idea to look at the surrounding text or the character's other dialogue for clues.