2048 × 256 table
A 2048 × 256 wavetable — 256 frames of 2048 samples each — is the de facto modern standard layout, popularized by Serum and adopted by many current wavetable synths.
Serum made the pairing ubiquitous, and even Vital — whose native .vitaltable format is JSON rather than audio — exports its own tables as 256-frame, 2048-sample WAVs, which is why a packed WAV at this size imports almost everywhere. The dimensions are practical rather than sacred: 2048 samples give each frame room for 1024 partials below Nyquist, and 256 frames cover plenty of timbral motion while keeping the whole table under twelve seconds of mono audio at 44.1 kHz.