A morse key is a table that makes it easy to decode morse code
How to use the morse key
You read from the top. Each dot moves you down and left, each dash moves you down and right. That's all there is to it, really.
Example use: Take the message "---/-.-"
Three dashes move you down three times to the right. T-M-O. "---" = O
Next character: Go right, left, right. T-N-K. "-.-" = K
The message was "OK".