using (OleDbConnection connDBF = GetConnection(PathToFile))
using (OleDbCommand cmd = connDBF.CreateCommand())
            {                
                cmd.CommandText = @"INSERT INTO " + TableName + " (Field1, Field2....Field17) VALUES (" + MultiplyParams("?,", 17) + ")";

                connDBF.Open();
                foreach (XElement rec in Recs)
                {
                    cmd.Parameters.Clear();
                    AddParamToCommand(cmd, "Field1", rec.Element("Field1"), OleDbType.Date);
...

    using (var connDBF = new OleDbConnection(ConnectionString))
    {
        connDBF.Open();
        var tbl = new DataTable();

        var adapterDBF = new OleDbDataAdapter("SELECT * FROM " + TableName, connDBF);
        adapterDBF.FillSchema(tbl, SchemaType.Source);
        var odcb = new OleDbCommandBuilder(adapterDBF);

        foreach (XElement rec in Recs)
        {
            tbl.Rows.Add(
                new[] {
                    rec.Element("Field1"),
                    ...
                    }
                );
        }

        adapterDBF.Update(tbl);