How to use ST-LINK Utility
Just from looking at it for a few minutes,


Size - The number of bytes in the hex file. Changing the number doesn't seem to do anything..
Data Width - Changes the representation in the columns of the data display, from 8-bit bytes to 32-bit words. Seems to do nothing else.
See #2. Additionally, the 32-bit display turns the byte order around into a more readable big-endian format for every 32-bit word. (the memory is organized in little-endian, obviously)
That is the address of the data in the first column. You can see that there are 16 bytes displayed (or 4 32-bit words depending on the Data Width setting). If you take the first number, 0x08000000 and add 16 to it, you get 0x08000010 in hexadecimal, which is the second row's starting address and heading.