how to keep the content of a subform on same page.

Hello

I have a subform see attached file. it is only fixed lines  for totals  and the vat is a table which may contain variable rows in many rates are available

Some times half of lines are split to next page if no space available.

In that case  i would like to put the whole subform content in the next page. So I dont know how we achieve this;

Thanks a lot for your help

Tahar