How to save the serial data with Serial Port Terminal?
As can be derived from User Manual (Help -> manual) "Advanced Serial Port Terminal allows you to send data blocks or whole files down the serial line or redirect everything you receive from the communication port into a file. You may use it for debugging and logging purposes or simply connect two computers using null-modem cable. "Send ASCII File" and "Send via X-modem" options open file selection dialogs to send ASCII file or any file correspondingly. "Receive ASCII File" and "Receive via X-modem" options open "save as" dialog to save incoming data into a file."
To know more about the option go to Help -> User manual -> How to... -> ...receive ASCII file.