When using Writer, how can I keep columns on the top half of page but remove them from the bottom half?

LibreOffice Writer Version 4.3.7.2

Page has 2 columns that I only need for top half of page. I want to remove the columns from the bottom half of the page so I can insert a table. Currently, I can only see the left half of the table. Thank you.

You should use the normal page layout and for the part, were you want 2 columns, you insert a section. The sections has it own options to determine columns.