Pensive they sit, and roll their languid eyes,
Nibble their toast, and cool their tea with sighs,
Or else forget the purpose of the night,
Forget their tea - forget their appetite.
See with cross'd arms they sit - ah! happy crew,
The fire is going out and no one rings
For coals, and therefore no coals Betty brings.
Keats is describing the English upper class and what appears to be the traditional 5 o'clock tea time.