In addition to effective headings, a bullet style presentation is strongly recommended. Your abstract should be an exception to this rule. You should be able to print this out as is. Take advantage of the work you have put into your tables and graphs. Since tables and graphs summarize information, you should try to include these as best as possible.
Pictures say a thousand words.
Do not put the tables and graphs at the end. Embed them into your text at the appropriate place in your poster. Be concise and to the point. Be sure to include title and your names. If there is enough room, include a reference section.