Minimum Worksheet Scenario
The smallest possible (blank) sheet is as follows:
<worksheet> <sheetData/> </worksheet>
The empty <sheetData> collection represents an empty grid; this element is required. As defined in the schema, some optional sheet property collections can appear before <sheetData>, and some can appear after. To simplify the logic required to insert a new <sheetData> collection into an existing (but empty) sheet, the <sheetData> collection is required, even when empty.