Latex multicolumn spans over more than one page

I have a Latex file that consists of a table that has merged columns that spans over more than a single page (less than 2 pages), but I didn’t found a way to get this to work. The results are unwanted page breaks (half a page remains empty before the table begins). I’m using the multicolumn function. Is there a proper way to get this to work or do I have to do a dirty hack that it looks like it should. But I don’t like to go this way. Important to know is that my text except of the left part of the table spans over the whole page with, it’s not a two column layout you can often seen books. Thanks in advance for any hints.