Hi -Amon-
That's what you should see. Each pair represents one
8-bit byte. Each line in hexedit is 16 bytes long. Thus
48 bytes is 3 lines. On the fourth line over on the right
in what's called the ASCII window you should see DDS
and in the hex window for the fourth line you should see
the three hex numbers 44 44 53 which are the hex codes
for the upper case characters DDS.

Make sure you've backed up this file. Then you can cut
the first three lines and save the file as filename.dds.
Then you can open it in Photoshop but you must have
the nvidia DDS plugin for Photoshop or it won't recognize
the file type.