const byte maxCount = 5;
const byte maxStringLength = 20;

char messageList[maxCount][maxStringLength] = {"str0", "str1", "str2"};

void setup() {
  Serial.begin(115200);
  // print all the strings (some are empty)
  for (byte i = 0; i < maxCount; i++) Serial.println(messageList[i]);

  // you can use strlcat to concatenate without overflow
  strlcat(messageList[0], " and more", maxStringLength);

  // you can use strlcpy() to initialize a string without overflow
  strlcpy(messageList[3], "some new text 3 ", maxStringLength);

  // print all the strings (some are empty)
  for (byte i = 0; i < maxCount; i++) Serial.println(messageList[i]);
}

void loop() {}