[antonvs]

No, that's just the vacuum state of any of the standard quantum fields.

"Field" is being used there in its general sense, of a quantity that has a value for every point in space and time. It's saying that in a (region of a) quantum field that contains no activity, there are nevertheless random fluctuations, which can themselves be modeled as a field. But they're not separate from the quantum field that gives rise to them - they have all the same fundamental properties.