Drupal Front end Form with fields with option to add More Fields
Assuming that "Name of Stocklists", "Sales as on Date", and "Closing Stock Value" are all CCK fields, you should be able to do this using Field Collection (https://drupal.org/project/field_collection).

1) Install Field Collection

2) Create a field collection field on your Report content type. Use the embedded widget. Be sure to make the field multi-value / unlimited values.

3) Go to admin/structure/field-collections and click Manage Fields for the field collection you created.

4) Add the 3 stock text fields to the field collection.

5) Now on the Report add/edit forms, you'll have the "Add Another Item" button.

To align the fields in a row, you should be able to use CSS. To make the button a +, you should be able to use hook_form_alter() or hook_form_report_node_form_alter().