If the number format of a range is not Text, the range is considered to contain data.
When transferring data from Excel to Mathematica:
See Overview for more details.
Data is handled the same way, whether you use the Clipboard, read and write from a macro, or use the DATA worksheet function.
The EVAL, EXPR, and RULE worksheet functions, however, assume inputs are Text, regardless of their number format, because they build Mathematica expressions from their inputs.
