The IRS only looks at the first 4 letters of your LAST name, the SS# and the year of birth in order to efile ... everything else can be dead wrong. So unless you must enter all those names for some unknown reason all you need to enter is a first and last in the program. Middle initial is not required. As already mentioned you could enter your first & 2 middle names in the first name box but be aware there is a 35 character limit for your entire name so it may be reduced automatically.
