That seems perfectly breathable to my knowledge: helium, xenon, and other noble gasses don't tend to interact with anything (hence "noble"), and so the only problems they cause have to do with them displacing other things. For instance, a person can breathe 100% helium without it causing any health problems—the issue is the 0% oxygen.

However, your planet will need stronger gravity than Earth in order to hold helium in the atmosphere. Earth's gravity isn't strong enough to keep hydrogen and helium around, so they'll dissipate off into space over time. (We get helium nowadays from nuclear fission happening deep underground, and hydrogen from breaking apart water, rather than extracting them from the atmosphere.)

You'll also want CO₂ for the plants to use, but that would fall under "other" (and you don't need very much). And you probably want some water vapor too, but that doesn't directly impact its breathability.