Hereby an update of my progress with exploring X2CRM (v6.9 by this time).
As mentioned in the previous post is want to import Call Logs from a former CRM to X2CRM.
After diving deep into the export csv which i exported in my X2CRM installation, i noticed that there was a field which indicates the type of action. The field Action Type.
When the field Action Type contains: calls
you have the indicator that put the information you import to the publisher as a Log Call.
So when you make you import csv for call-logs, make an extra field with the name: Action Type.
When mapping the import file, map this field to Action Type listed in the mapping options.
You als have to indicate to which accounts the information must be related to. I did this by making a field: contacts which i made the field to match. There is a disadvantage to using a field; contacts because it's not realy unique. So after import you can notice that some relations are not good. For now, to me, this was a sufficient solution. But with larger databases and imports it is better to think of and create a unique key in your csv file that makes the exactly right matching.
May my experience help anybody who is looking for how to import data into the Publisher fields.
And if you have any questions or suggestions, please reply to this post.