For previous List & Label versions from version 11 on, proceed as follows: Use the following designer function that returns the space left within the current table. You can choose to receive the percentage (default) or SCM value (1/1000 mm) of the remaining table space.
You can use this function to trigger conditional page breaks e.g. before group headers or sub tables. Select the table in question in the table structure window and enter a “Page break before” condition. If for example you’d require a page wrap whenever the remaining space is less than 15% (as the header area for the sub table would require at least this space) your page break condition would read:
In order to keep the header area of an arbitrary sub table together with its data, simply adjust the comparison value as needed.