Most tables that utilize an acrylic platter do so specifically to couple the record to a surface with similar characteristics so that vibrations (from the stylus tracking in the groove) travelling in the record will be transmitted to the platter and dissipated in the platter. If you use a mat between the two, you will compromise this particular design feature.
Acrylic is a quite soft surface that can be easily scratched, even when all you are doing is trying to clean it or remove dust. Do not even use paper towels in the cleaning process. I use the special eyeglass cleaning paper towels for this purpose. I keep the platter from collecting dust by covering it when not in use with a sacrificial record (a Charlie Rich album someone gave me that I have never listened to, although it is, now the record that spends the most time on my platter).
Acrylic is a quite soft surface that can be easily scratched, even when all you are doing is trying to clean it or remove dust. Do not even use paper towels in the cleaning process. I use the special eyeglass cleaning paper towels for this purpose. I keep the platter from collecting dust by covering it when not in use with a sacrificial record (a Charlie Rich album someone gave me that I have never listened to, although it is, now the record that spends the most time on my platter).