To delete records from Salesforce.com in bulk using XL-Connector, you will only need a column of record IDs in your Excel spreadsheet. These IDs don’t even have to belong to the same object. You can pass IDs of different objects to the Delete operation and it will delete them all. In practice though, you will in most of the cases be deleting records of the same object in one Delete operation.
So as long as you have a column of record IDs in your spreadsheet, you can select the rows you want deleted from the Salesforce.com database, click Delete button, confirm the deletion, and you will be all set.
Ironically, out of all DML operations, Delete is the safest one. Records deleted by the Delete operation from XL-Connector can be restored from the Salesforce.com Recycle Bin for the first 30 days after deletion.