you may try visibility option ...
say Suppose u have two tables in a report and second report is the sub-report of 1st one....
now say u want to show 1st table when report opens and hide the second one ...so wht u can do is go to 2nd table properties and select visibility option to hidden, select toggle option from which u want to show ur 2nd table (that may b a text box , if u click on that text box the second table will b displayed)
c if it helps u....