The problem is that MONTH field in the Sheet1 table is a numeric field in date format MMM, while in the inline load it is a text field. One way to fix it is to convert it in text on the excel load, for example:
text(Month(Date1)) as MONTH
In general, it is not a good idea to use this inline. You have Date fields in excel - use qlikview functions to create month, quarter, even half. See examples of master calendar on communuty for ideas.