Generating dual rail power from a MAX3232?
Charge-pump based voltage generators, like the MAX3232 are generally very limited in terms of output current (it seems that all the MAX3232 datasheet guaranties is a voltage of +/-5V at 2.5 mA load). Beside, they are not very efficient at compensating output transients. If the required output current is higher than a few 10 mA, use a true step-up (boost) DC/DC converter, like the LT1300 from Linear. I even found this part: LT3582-5 (from Linear also), which seems to do exactly what you want. Other similar parts may exist as well.

If your application is noise sensitive, you have no guaranty at all regarding this point in this datasheet... I am afraid that you can't just guess what the output noise would be!