Reserved - edit

[Wjames]

The muffled room in which we dine
at tables doomed for eight or nine;  I don't really see how the table is "doomed", unless it's supposed to tie in at the end with the killed time somehow? I think something like "groomed" might be better.
the champagne glasses deftly clinked,
though champagne isn’t what we drink. What do you drink?
The chicken’s textured rubber duck  I like this line.
and vegetables are overcooked; the half-rhyme sort of works for me here.
rain dribbles down the window-panes;
the walls exhibit aged stains. This only works for the syllable count if it is "age-ed" which is a little weird.
The waitress frowns absorbed, remote;
you shape a sound, you clear your throat you might want to change the second "you" for something like "and". There are three "you's" in this line as is.
then whisper something indistinct; This line doesn't say much.
our stiltedness makes others wince. This rhyme doesn't work for me at all, it's two completely different sounds.
The portraits yawn, the music plinks;
a napkin’s drawn to bloodless lips. Neither does this one.
So many seats remain unfilled
to celebrate how time is killed. How is time killed? Stuffy stuck-up nights out like this one? Then why aren't the seats filled?
 

Most of the poem reads smoothly, but I can't really glean any overarching meaning from the empty, presumably "reserved" seats, and the passage (wasting?) of time. Hopefully my thoughts are of some use to you.