Loading a table with input from two different input files
Create a table (t1) with columns matching the columns of one file.  Load that file into it.

Create another table (t2) with columns matching the columns of the other file.  Load that file into it.

Now create the main table (if it does not already exist).  Load it with something like

INSERT INTO main (a,b,c,d,e)
    SELECT t1.x, t2.y, t1.z, t1.w, t2.v  -- in whatever order is correct
        FROM t1
        JOIN t2 ON ... -- explain how the two tables (files) need to be paired up.