Using Chebyshev polynomials in wavetables
Chebyshev polynomials are mainly used for waveshaping, where an input signal is distorted by applying a memory-less non-linear function to it. This shaping function is stored in a look-up table (wavetable). If you use Chebyshev polynomials, then the polynomial just defines the shaping function, and the wavetable is generated just like for any other shaping function.

If the output is given by $y=f(x)$, where $x$ is the input, then the wavetable contains values $y$ for a given range of input values $x$. The function $f(x)$ can be defined in any desired way, and one way to define it is to use Chebyshev polynomials, which for a pure sinusoidal input generate a given harmonic.