You can save the worksheet as a comma-delimited .CSV file and import it with the free QSCImport utility (from CustomerSource) or with a third party import utility like EMS' MS SQL Data Import. Most third party tools will have the same shortcomins as using a query...
Using a query or set of queries is challenging if you want to add Supplier info like reorder number, MPQ, etc. These fields are not part of the Item table but part of the Supplier table.
It'd be easy to create a series of query statements in a column of your spreadsheet with a formula like this one: ="INSERT INTO Item (Field1, Field2...) VALUES ("Value1", "Value2"...)" where 'ValueX' refers to the appropriate cell.
Best of luck, Tom