Hi Aitzol, tables are not displayed properly because the report is A4 size in portrait. You just need to convert portrait document in landscape mode then it will be in proper order. First open your sxw file in there go to Format->Page menu there you can see Orientation:Landscape.

You can also set page size from rml. Generally template pagesize is (842,595) for landscape report. You can also change in frame tag as per your need.

  <template pageSize="(842.0,595.0)" title="Test" author="Martin Simon" allowSplitting="20">
    <pageTemplate id="first">
      <frame id="first" x1="35.0" y1="35.0" width="772" height="525"/>
       <header>
                //Your Company header
      </header>      
    </pageTemplate>
  </template>

I finally found the solution to the problem with the page landscape layout. The problem was that although the page was in landscape mode, the page frame remained in portrait mode.

I found that all dimensions in the rml were ok and the problem was somewhere else, in the report's python file to be precise:

report_sxw.report_sxw('report.modulename.product.label','mrp.production','addons/modulename/report/product_label.rml',parser=order,header=False)

The problem has been solved by adding "header=False" parameter to the report_sxw method call. It seems that by not adding this parameter, OpenERP modifies the page layout in order to add the header, which is configured to be in portrait mode. This was overwriting the settings for landscape mode in my RML file.