I have a slider type dimmer on a switch for a chandelier in the foyer of my house. When the dimmer is in use, the switch plate tends to tbe hot. Is this normal. The house is less than 10 years old.

The dimmer is to small to be used with the total wattage of the lamps. You need to purchase a larger dimmer.

Check to see the wattage of each bulb and total them up. Add about 15% to that and that should be enough to properly size the new dimmer.