fire65-
Because, unless you are liberal with the adhesives, edge banding will not "seal" the edges... Alongside that, most edge banding tape is iron-on which is far from "sealing" it. Most commercial edge banding machines are a hot glue, which is applied just enough to stick... not to seal it. (Excess glue takes time to clean up and slows down production) Like you said, good chip protection and prolongs life, but in itself, does not seal the edges.
Eric-
You could just use a seal coat finish. We use MDF in a machine table because the surfaces across it's thickness are parallel to each other and the surfaces are consistently flat. Those qualities are important in a machine table. If you do a paint-out or other finishes (without sealing first), then if it is thick in one spot or you overdo it with too much at one time... then besides the MDF soaking in more and risking swelling, the thick finish itself risks it not being that flat anymore from the inconsistent thickness of the finish. (If you were real picking about that minute amount... talking brush-on application.)
Even in a paint-out, with MDF, you seal it with a primer or some other type of sealer first. Sealing it will a seal coat would be the best option for that in that application. That would seal the material without adding anything to it's thickness. If any finish was applied after being sealed with a seal coat or primer, finished over that sealer, then it would take less and be more consistent, without risk of that finish soaking in too much.
Do not use paste wax. A lot of times paste wax on MDF tends to soften it's surface and ends up making it's surface somewhat gummy. The material will then stick to it. Not all the time; but often enough for me not to do that again.
Unfinished MDF has a tendency to soak in any moisture very well. That is why gluing is so easy with mdf. Even if you think you live in a low humidity area... sealing = good protection, material slides better, reducing drag and causes the table to wear less. It doesn't hurt anything to seal it and be safe.
Did you call the number of Freud customer support in the docs that came with the table? What did they recommend?