Use the first 100 (default) Excel data rows to preview and calculate data types: This determines the number of rows that the preview displays, and the values that affect the automatic mapping feature.

Analyze and try to detect correct datatype based on column field contents: Attempts to analyze the data and determine the data type for the column. The column type is defined as VARCHAR if it contains multiple types.

Add additional buffer to VARCHAR length (round up to 12, 25, 45, 125, 255): When the data type is automatically detected and is set to VARCHAR, then it calculates the maximum length for all rows within the column, and rounds up the maximum length to one of the defined lengths above.

If disabled, then the VARCHAR length is set to the length of the longest entry in the Excel spreadsheet.

Automatically check the Index checkbox for Integer columns: If enabled (default), columns with an Integer data type will have the Create Index option enabled by default.

Automatically check the Allow Empty checkbox for columns without an index: If enabled (default), columns without the Create Index checkbox checked will automatically enable the Allow Empty configuration option.

Use formatted values: When enabled (default), the data from Excel is treated as Text, Double, or Date. When disabled, data is never treated as a Date type, so for example this means that a date would be represented as a number.

Remove columns that contain no data, otherwise flag them as "Excluded": If enabled, columns without data in Excel are removed and not shown in the preview panel. If disabled (default), these columns will exist but have the Exclude Column option checked. This option was added in MySQL for Excel 1.1.0.