You can remove bottom border by writing this below line in viewdidLoad,
self.tblMyTable.separatorStyle = UITableViewCellSeparatorStyle.None
And Remove left padding by writing this in cellForRow,
cell.separatorInset = UIEdgeInsetsZero
cell.layoutMargins = UIEdgeInsetsZero
Update for Swift 3.0:
cell?.separatorInset = UIEdgeInsets.zero
cell?.layoutMargins = UIEdgeInsets.zero