A person sits down to eat in front of the television, and the evening news comes with the meal. The opening image is bleak: the day itself seems to be ash, burnt out and served up in a dish. Nothing in the first two lines suggests appetite or comfort. The news is just something to swallow along with dinner.
The second stanza pushes back. The speaker's coffee becomes "an argument against" what the poem calls an "overbalance of propriety." That phrase is a little stiff, and it seems to describe the tidy, well-behaved ritual of the evening: the polite meal, the sober broadcast, everything in its proper place. Coffee, bitter and stimulating, is the small act of resistance. It wakes the speaker up instead of letting them settle into numbness.
The mood is wry, tired, and slightly restless. The speaker doesn't storm off or switch the set off. They just quietly disagree, one sip at a time.