This Excel file didn't fail because it was too large. It failed because the Excel has four values that are over the max value of int32
The int type represents signed 32-bit integers with values between –2,147,483,648 and 2,147,483,647 . int is just an alias for Int32 - it's defined in the C# specification. Therefore int.MaxValue is the same as Int32.MaxValue which will always be 2147483647.