Oh! So the intended workflow is SetObjectArrayParameter (this also applies to any other UObject-based parameter type, e.g., pretty much everything that doesn’t have a dedicated parameter command).
Wave Tables are a bit different! They use the curve editor - outside of MetaSounds, you can create an asset called a WaveTableBank (right-click on Content Browser and go to Sounds->WaveTable->WaveTableBank), and you can access the data in it via the GetWaveTableFromBank. Generally you’re going to want to use the WaveTable you obtain for WaveTableOscillator (if you want it to be at an audible rate, like a sine wave), or WaveTableEnvelope (if you want it to control a parameter like volume slowly over time).