I'm not sure i understand, your issue with Composer was making a chart? Why would you try to make a chart in Composer, it is a page editor not an image editor, why not make the chart in a tool made specifically for charts and use it as an image? Also what tables and colspan/rowspan have to do with charts?
Sorry, I meant table and started saying so but I cut that part out at some point. I also tried lowriter; editing tables and rows and cells is better, but not by much.
