In a common, old style, fluorescent tube, yes the ballast is just a choke. When the tube fires, the gas inside ionises, and becomes conducting. The choke limits the current that can flow through the ionised gas to dI/dT. Energy is stored in the choke and released on the next AC cycle. Because the impedance of the mains is effectively zero, without the choke, the ionised tube would appear as a near dead short across the mains without the choke.
I made a post about a week back, "heads up", in which I advised that a small resistor in series with the tube may be necessary with some inverters.
It is unfortunate that the term "electronic ballast" has come into common use. The mass produced cfl lamps have a rectifier and inverter built into them, and called "electronic ballast". I have seen these lamps run off an inverter from 12 volts, but you have to rectify the high voltage, and regulate it to about 350 volts.
Amanda