Gel Desiccant

Can table salt be used as a desiccant in the same way as silica gel?

No need to guess ! The straight answer is ‘no’.

Here is the fine print -

Saturated solutions of various salts can be used to control the relative humidity of the air above the solution, and can be used as calibration systems for hygrometry. Some examples are as follows (all at 20C) -

NaCl – 76% (this is really quite damp)
KCl – 86%
MgNo3 – 55%
K2CO3 – 44%
MgCl – 33%
LiCl -12%
KOH – 9 (pretty dry)

In most cases, if the air above a sample of the dry chemical has RH exceeding these figures, the salt will absorb atmospheric moisture and eventually dissolve in it to form a saturated solution. The air above the solution will then have its RH reduced to the figures shown (assuming a sealed container).

Eating Desiccant Silica Gel