Try to import each file into a separate table and create a table for each month's data. You can use the Import/Export Wizard, BULK INSERT statement, or an SSIS package.

Once imported, you can use the join statement to combine the data as mentioned below :

SELECT *
FROM Table_January
JOIN Table_February ON Table_January.ID = Table_February.ID
-- Add more JOIN clauses for additional months if needed

This will combine the rows from Table_January and Table_February based on the matching ID values.