Powerpivot, need connect fields in two table, which has duplicates

Hello,

I am using excel 2013, and w7 enterprise

I have two tables in powerpivot, and I need to link them.
Many rows are equally but some are different.
This is not big files, both around 300.000 lines and around 20 columns.
These files are not identical.

I am not keen to merge this two tables into one, unless I can do it automatically.
Manually is too risky.

I was thinking to link the files through social id or document number.

The problem is, I have duplicates values. Is there only possible to link, one to many?

In attached file you can see some demo.

Hello CK76, this is just a sample. There are several columns which are different.

... sample should accurately represent your actual data set.

At any rate, you should do transformation and clean up in PowerQuery. That remains unchanged as you can't relate the columns.

sktneer, this seems to work. Yes I think socialID is best connection.

ck76, Im sorry if I were not accurate. I didn't want to post my data. Probably my example was not good enough.

Thanks for the help.