I think they’re referring to a fixed width for the palette, which has previously been requested: Fixed Column Width Palette
Many older software display palettes in a 16x16 grid of up to 256 colours, and I suspect this is what they want to emulate.
If they’re referring to the size of the swatches, they can be adjusted in the palette Options, though there are only three size options, and their exact size depends on your screen scaling setting.