Is there a limit to how much you can cache in an array of objects

Code:
function report_list_item( new_category_id, new_subcategory_id, new_report_id, new_report_name) {

  this.category_id = new_category_id;
  this.subcategory_id = new_subcategory_id;
  this.report_id = new_report_id;
  this.report_name = new_report_name;
}
I popup a search window and use this structure to store reports that were found.
I create 100 of these every time a search is done, stored in an array. Right now I am seeing the browser freeze up after a few tries. But when I kill the popup with the [x] button everything works ok again.

I am wondering if the space allocated to the list items doesnt go away and that I am just filling it up.

I already have a HUGE array of items loaded in the main window in a JavaScript array.

Does this sound correct? Or could it be something else I am doing?

-S. Bob