Split string to max size of 30 - arduino-c++

Question

I need to write function that will split my large string into arr of max size 30. I tried something like this:
byte packetNumber;
String Text = "Lorem Ipsum is simply dummy text of the printing and typesetting industry.";
void loop(){
convertData(Text);
}
void convertData(String toSlice) {
packetNumber = ceil((float)toSlice.length() / 30);
byte mod = toSlice.length() % 30;
char Arr[packetNumber][30];
byte buf = 0, buf2 = 30;
for (byte x = 0; x < packetNumber; x++) {
for (byte y = buf; y < buf2; y++) {
Arr[x][y] = toSlice[y];
Serial.print(toSlice[y]);
Serial.print("----->");
Serial.print(y);
Serial.print("\n");
}
if (x == packetNumber-2){
buf+=mod;
buf2+=mod;
}
else{
buf+=30;
buf2+=30;
}
}
Serial.print(Arr[0]);
Serial.print(Arr[1]);
Serial.print(Arr[2]);
Serial.print("\n");
Serial.print(toSlice[32]);
Serial.print("\nilosc pakietow: ");
Serial.print(packetNumber);
Serial.print("\n");
}
But the output is:
Lorem Ipsum is simply dummy te⸮⸮xt of the printing and typesetJ
I think it s because it takes too much memory because it overrides my other variables with this data. Do you know any good solution for this?