Problems in exporting database columns of a table with values as Excel file

Question

I want to list down all columns of a database table in an Excel file. I have written the code below to do that:

foreach (DataColumn column in table.Columns)
{
    columns.Add(column.ColumnName);
    DocumentFormat.OpenXml.Spreadsheet.Cell cell = new DocumentFormat.OpenXml.Spreadsheet.Cell();
    cell.DataType = DocumentFormat.OpenXml.Spreadsheet.CellValues.String;
    cell.CellValue = new DocumentFormat.OpenXml.Spreadsheet.CellValue(column.ColumnName);
    headerRow.AppendChild(cell);
}

My problem: I am getting a list of other entity types in table as they are referenced there. I do not want to include these. They have no values, only type is mentioned. For example:

System.Collections.Generic.HashSet`1[QA.DataCommon.EntityDataModels.TableException]

I want only those fields in my excel which have a database column corresponding to it. I tried some ways by doing it reflection but was unsuccessful.