Why have resistors in a circuit down-stepping 230VAC
The 820 ohm is almost certainly for current limiting.

Without knowing more about the circuit it powers it's hard to be exact about the 27k, however, I think it may be to present a minimum load to the secondary to limit light or no load voltage (possibly to discharge any filter caps also and/or related to PMOS turn on battery/AC switch circuit to pull gate back to ground)
This is often used if the following circuit has no proper regulation (i.e. linear or switch mode)