Hi Serenity:
The Sim Arbitrary Wave indeed uses just such a table. However, you do have to insert the data manually. However, this is your lucky day. I've "drilled down" into the Express SIM arbitrary Wave vi, and converted it into a standard VI. From the block diagram, I replaced the ARRAY control with a Read Spreadsheet.vi. You should be able to put your wavetable data into a spreadsheet. I've attached an example. You might need to tweak it a bit, but it should get you started.
Let me know if you need any more.
Eric