1) use a <textarea> instead of an <input type="text"> field and you can make it much larger and allow scrolling.
2) Try updating lines 85 and 86 to:
$WA_columnTypesStr = "',none,''|',none,''|',none,''|',none,''|',none,''|',none,''";
$WA_comparisonStr = " LIKE | LIKE | LIKE | LIKE | LIKE | LIKE ";