econjack:
A 64x64 array eats 4096 bytes of SRAM and your Uno has 2K.
Oh my god. That is embarrassing. 
Thanks! 
jasit:
why don't you read everything in and then parse it once you get the enter key,while(Serial.available() > 0) {
myChar = Serial.read();
currentLine += myChar;
if (myChar == '\n') {
int spacePosition; // the position of the next comma in the string
spacePosition = currentLine.indexOf(' ');
wordOne =currentLine.substring(0,spacePosition);
wordTwo =currentLine.substring(commaPosition+1, currentLine.length());
}
currentLine = "";
}
Well, both my code and your code get to the same result, no? 