It goes on to state that you should set this only to the current recommended amount of 64K, and that this amount may increase in future releases of AppleShare.
This documentation is incorrect. AppleShare on the Server ignores the Control Panel RAM cache setting. AppleShare automatically allocates RAM for the foreground application, the stack, and itself, then turns all the rest of available memory into RAM cache.
This correction will be documented in AppleShare 1.1 with a release note.