Density range of table salt?
The density of $\pu{2.17 g/cm³}$ refers to the bulk density, i.e. within a crystal of NaCl.  In chemical engineering, the terms of powder density, tapped powder density and settled apparent density take into account for the air between the grains of a solid. Especially the later recognizes that there may be a difference between the solid simply poured into a container, and after light compression (still with air gaps between the grains) after applying a little pressure e.g. if you shake and knock the tin filling with freshly ground coffee powder.
References like this, this, this, or this .pdf state powder densities of $\pu{1.378 g/cm³}$ (fine table salt), $\pu{1.282 g/cm^3}$ (granulated salt, again from here), and $\pu{1.089 g/cm^3}$ (rock salt). From these values, your estimate of $\pu{1.40 g/cm^3}$ seems plausible.
However, these data lack to state the typical size of the grains (think about the diameter), as well as the dispersion of the grain sizes (presence of larger and smaller grains, equally known as particle-size distribution) of the samples characterized. Both influence the packing of the grains and thus the recorded density.  In this perspective, the softer / more airy harvest of fleur de sel possibly packs much less dense.