You cannot optimize XFA forms using Acrobat.You'll have to check your
form design in Designer for things that increasing the forms size.This
can be fonts, embedded images etc.There a a couple of tips from John
Brinkman you should
check:http://blogs.adobe.com/formfeed/2011/10/fix-layout-problems.htmlhttp://blogs.adobe.com/formfeed/2011/05/fonts-are-big.htmlhttp://blogs.adobe.com/formfeed/2010/09/xdp-size-matters.htmlhttp://blogs.adobe.com/formfeed/2009/11/linked_vs_embedded_template_im.html