IRP - I/O Request Packet; a request sent to an I/O driver
MJ - Major Function Code
CREATE - request to create a handle ("open" for us non-Microsoft / normal folks)
WRITE - fairly obvious
CLEANUP - ditto
CLOSE - close the handle
VCP0 - name of the device (Virtual COM Port 0); "COM7" is the DOS name
"Length 2: 97" - I'm not familiar with PortMon but I assume that to mean two bytes were written: the character "9" (0x39) followed by the character "7" (0x37).