Table sizes in Csound are user-defined. You can also use user-defined tables in Pd with [tabosc4~]. I think what may be a little more important for the differences in sound is the fact that csound and Pd use Lagrange interpolators and supercollider uses an Hermite one for the cubic interpolation within oscillators.

Matt

Pd's oscillator wave tables are 512 samples.  Supercollider uses 8192 - not sure what CSound uses.  The efficiency of the SC code allows for large sample tables and bigger FFTs, which certainly help make a 'smoother' sound.

It would be interesting to hear what happens with 16x larger tables in Pd.