In dynamic fashion setting a custom class to a cell in a row

If you need to set CSS properties for a row, then what you can try is to use the predefined CSS class of the table along with the custom class. For Example

.sapMListTbl .<your class name> {
   margin: 10px;
   color: #ffffff;
}

Also, you can opt for a formatter while applying the new class along with your model classes.