I'm not sure why it won't save in dbf. I was able to save it using Excel 2003. Is that you can't save a dbf file or that the AddXY data tool won't work to convert it to a shapefile?
Anyway, try saving it to a CSV file instead. That worked for me.
I have a few comments on the file format too.
1) Make the LongDD values negative. ArcGIS requires that longitudes west of the Greenwich meridian be negative.
2) I'm a bit confused on the seconds fields. Seconds should be between 0-60, so what's 679? Is it really 06.79? I didn't think about until I had checked one of the DMS-to-DD calculations and entered.
3) If the seconds values are 06.79 or something similar, you may want to increase the number of decimal places in the DD fields. 1 second in the lower 48 states is about 30 meters and is, very roughly, 0.0001 when working in decimal degrees. If you have 06.79 precision in seconds, you should increase the DD precision 5 or 6 decimal places.
4) Since you don't state it, just to be sure! Convert these tables to a shapefile of coverage. You may want to assign them the NAD83 geographic coordinate system rather than WGS84. WGS84 and NAD83 are within a meter of each other. There are more accurate transformations between NAD27 and NAD83 than there are between NAD27 and WGS84. Calling the input data NAD83 will let you use the NAD_1927_To_NAD_1983_NADCON transformation (don't worry about the directionality; the software will handle it automatically).
Hope this helps, and makes some sense!