When you store the Import Records script step, the source table is stored as of the latest manual import. Therefore, you should:
1) Perform the manual import.
2) Edit the Import Records script step in the target script.
3) Save the script.
4) Repeat for each Import needed.
This will save the source tables appropriately.
Thank you very much for your help.
Usually I do the steps you mentioned when I have a file that I know the name.
But here, I don't know what will be the file name on the user's laptop.
This is why I was using a variable to tract the file and do the import (and I couldn't define the table, because I don't have a real file during programming - there was no tables to choose from).
What I have done here is that I used a sample of the file --> edited the import script --> changed the filename back to a variable (without reopening the import window)
And all went in the good way.
We do sometimes need a hint.