When adding a spreadsheet, use the Labels option equal to None, position it on the line where it starts:
LOAD A as [Serial Number],
B as [Cost],
C as [Class],
D as [Other ID]
<Path of your Worksheet>
(ooxml, no labels, header is <Place on which line begins> lines, table is <Your Sheet>);
If you rename the labels you will have no problem loading, understand?