Yes, A script can use Import Records to import the data from the tables in File 1 into the tables of file 2. One Import Records step for each table found in both files.
But be careful of ID fields that auto-enter serial numbers. There's a very high probability that when you import your data you be producing a table where more than one record has the same ID number.
Since each import records step produces a found set of records for its specified target table, you can use Replace Field Contents immediately after the import to modify the value in such fields to keep them unique. One trick that I have used is to use the calculation option with this type of expression:
SerialNumbeField + 0.1/ change the value to add with each new file of data to merge
This produces a serial number value where you can see the original value (the amount to the left of the decimal) but which does not match any previously existing record in your database.
Since such a field is typically used to link to records in other tables, you'll need to make an identical update to the match fields of any other tables in your database after importing the data from those tables.
Once you are through importing records, you'll then need to review the next serial value settings on all such fields to see if any need to be set to a different value. (using the above method should avoid the need to change such settings, though.)