What property allows an RF choke coil to have little effect on signals meant to flow through the coil?

Inductive reactance is directly proportional to frequency. This means an inductor's opposition to alternating current increases as frequency goes up, and decreases as frequency goes down. An RF choke is designed to block high-frequency radio signals (high reactance) while allowing desired lower-frequency signals, like audio or DC, to pass through. Because the choke has low reactance at low frequencies, it presents almost no opposition to the desired signals meant to flow through the coil.