there is the file_get_contents php function which reads the file into a string.
You could create a loop to look through all of the files in the upload directory and perform an insert of the files contents into the database using the file_get_contents php function:
file_get_contents
you wold probably want to store the file name in another column as well and check to see if the file has already been imported so the file contents only get added to the DB once. I dont have any specific examples on this, but if you are comfortable with PHP coding, it shouldn't be to difficult to figure out.