Thanks for contacting us here about this extension.
On a long non-scrolling table - when I filter a field so it only shows a few rows - the table stays the same size and there's a huge blank area below it.
When you do a search on a TablePress table, it resizes the table and avoids a large blank area - which is a better user experience - please consider implementing that in the future.
It could be something wrong at your site. The table will be resize automatically when you filter a column, you can check our demo: https://www.joomunited.com/wordpress-demo/wp-table-manager-presentation/
In order to have a deeper look at your problem, please drop us a ticket (menu Support > Ticket support). Our developer in charge will take a look at that.