Suppressing contactor coil inrush, is this possible?
You don't want to suppress the inrush, but rather, find a different way to supply the inrush current &mdash; it is required for the contactor to operate properly. It needs about 30 A for up to 50 ms, or about 1.5 C.

If you are willing to allow your supply to sag by, say, 6 V, then you need about 1.5C/6V = 250mF of capacitance to supply the short-term current.

You can use a low-value resistor, thermistor, or inductor between the power supply and the capacitor in order to isolate the power supply from the surge.