Agree with Rob.
I'm new to Qlik too and I actually found that to be quite amazing of Qlik Sense. In regular SQL it would have been multiplied but not with Qlik associations! I still struggle getting my head around it...
Gwendly please put some simple sample data together and keep us posted. I'd like to see that issue you're having
It seems my problem is somehow in the source data in our database. If I pull data from January 2014 onward (which is 30,000 activities), the numbers are correct. When I pull data prior to January 2014, I am getting crazy numbers that I can't understand. Because 2014 onward is clean, I think my QlikSense table configuration is fine. I am still researching.
Because I am so new to Qlik, your answers were still a huge help. I was running around in circles trying different was to join and not join. (in the SQL, in the Load script, linking in the data manager). Your answers helped me know what my goal configuration SHOULD be, and which it now is... they are loaded as two different tables in the Load Script, with a commonly named key field, resulting in a natural linking in Qlik.
If I am able to find out why I am having trouble with 2013 and earlier data, I will let you know.