Create an Apex class with a method that returns an array (or list) of strings.

StringArrayTest.cls

public class StringArrayTest {
	public static String[] generateStringArray(Integer numOfStrings) {
        // Create a generateStringArray object
       String[] stringArr = new List<String>();
       for(Integer i=0;i<numOfStrings;i++) {
            stringArr.add('Test '+i);
        }
        
        return stringArr;
    }
 
}