Form development

Experts,

Its not advisable to make a form with a subform built off of the same tables?  
I ask because displaying all information in the form might make the form hard to read.  i have seen professionally built databases where you click on a part of the form and other areas (subforms) update.  Is each subform typically built off of a separate table?  I believe so however a separate query to find data in those forms and subforms could require all of the other subform tables.  I mean you would have to drag in all of those separate tables, correct?   I guess it shouldnt be a big deal if all the tables were linked properly.  

if the form was instead just built off of 1 table then queries would require only 1 table,, correct?   I am trying to figure out the benefit of having multiple tables i/o havin 1 table (in this case).

thanks...