QTableView Display obscured

The QTableView column is very long, dragged out of the layout, and the data display is obscured by the layout.

code:
_tableView = new QTableView(this);
_itemTableModel = new ValueTableModel(this);
_tableView->setContextMenuPolicy(Qt::ActionsContextMenu);
_tableView->setAlternatingRowColors(false);
//_tableView->setItemDelegate(new ValueTableDelegate());
_tableView->setModel(_itemTableModel);
_tableView->horizontalHeader()->setSectionResizeMode(QHeaderView::Interactive);
_leftVlayout = new QVBoxLayout();
_leftVlayout->addWidget(_tableView);