How to Convert Plain Content on an Excel Sheet to a Table

The Fancypantsification of the Plain Vanilla Sheet

If you have data on a sheet that is stark and blah like so:

...and you prefer to give it a little pizazz, like so:

...all you need is the following few lines of code; all you might need to change in this code is the name of the worksheet (from "_xlWhateverSheet"), and the name of the source table (from "tablifiedSheet").

private Worksheet _xlWhateverSheet;
. . .
string tableStyleToUse = "TableStyleMedium9"; 
string nameOfSourceTable = "tablifiedSheet";
Range entireSheet = _xlWhateverSheet.UsedRange;
_xlWhateverSheet.ListObjects.Add(XlListObjectSourceType.xlSrcRange, entireSheet,
            Type.Missing, XlYesNoGuess.xlYes, Type.Missing).Name = nameOfSourceTable;
_xlWhateverSheet.ListObjects[nameOfSourceTable].TableStyle = tableStyleToUse;

Note: You can change the table style to use, too (tableStyleToUse) if you prefer something different than what is shown above. "TableStyleMedium9" is the style used by default when you manually create a table in Excel; it is visually pleasing (YMMV) and provides a filter for each column.