The @ symbol can also appear in regular formulas outside of tables when Excel thinks you're trying to reference a single value from a range. If you see it pop up unexpectedly, it usually means Excel ...

Excel's VALUE function has only one argument: where a is the value stored as text that you want to convert into a number.

Excel automatically adds parentheses when you select columns in a table with the mouse. This article explores structured references and the three situations where double square brackets are generated: ...