We have to know the product formed on reaction of ethyl iodide with triethylamine.
The product is tetraethylammonium iodide salt.
On reaction of ethyl iodide with triethylamine, a quarternary salt is produced which is ionic in nature. The salt is ionic and polar, it gets dissolved in polar solvent but insoluble in non-polar solvent.
As it is ionic compound, its melting point is high, it does not melt below 200°C.
The structure of the product (tetraethylammonium iodide salt) is shown below: