Chances are that you will need to review the script that is loading the data from your data base to pare down the elements and also ensure that QlikView is associating the tables correctly. QlikView associates data entities by column name (e.g. OrderNumber to OrderNumber). You may have like column names in different tables that you do not want to have associated (e.g a generic ID column). Use the script to exclude columns or alias column names. Check the Table Viewer (ctrl+T) to see what data model QlikView has built - this will give you some clue as to what and where you need to rationalize your load script.
If you've selected all columns (ie SELECT * From ...) for each entity, you may want to step back thru and select the columns you do want to have them named within the script and allow for the transform steps described above.