How to import a text file with more than 255 fields into Access

[OBP]

500 records will be fine.
You will have to change the line of code that sets the key field string (fieldcount = 25) to reflect the number of the key field in the second table and then add the string to the first table key field after processing the second table.
So you would need to move line

.Fields(63) = keyfield 'set primary key in tblImport2

to after the table 2 processing with this code

With rst ' process first table
    .AddNew 
    .Fields(whatever the key field is in table 1) = keyfield 'set primary key in tblImport1
    .Update 
            End With