Hi,
The resizing is easy to fix, just set a discrete width for either the form or the reference table within the form.
With respect to showing all records, do you mean all other purchase order line items within the system? If so, this is not the case as you can see the sub-total is only totally the line items related to this purchase order. If you mean that it is the sub-total of all of the line items within the purchase order, yes it is. If you are looking for grouped sub-totals of line items within the purchase order, just click on the grouping button, assign the value that you want to group by and assign a SUM value to the line cost field.
If I have misunderstood your issue, please elaborate.
Cheers,
Pete