The bottom status bar contains several panels. From left to right these are:

Data Monitor. By default this shows the current log record as it is written to disk (or at least as much as will fit). If you click on a byte in the RAM display, it will be displayed in its selected logging format. Click it again to revert to the original display.

Undo counter. This shows how many levels of undo are stored

Log file name.

SLCom status. This shows the state of the connection to the SPLat board. SPLogger automatically scans COM1 through COM4 looking for a SPLat board. You can click on this to isolate SPLogger from the board, and free the serial port. Click it again to re-connect. Isolating is convenient when you are alternating with SPLat/PC to debug a program in the board.