Append custom style to a GWT CellTable (in this case all cells)

CellTables have their own CssResource. To override this style applied to all cells in a cellTable, create a new css file :

/* Incremental changes from CellTable.css */ 
.cellTableCell {
  white-space: nowrap;
}

Then create your own CellTable.Resources interface :

public interface TableResources extends CellTable.Resources {

    /**
       * The styles applied to the table.
       */
    interface TableStyle extends CellTable.Style {
    }

    @Override
    @Source({ CellTable.Style.DEFAULT_CSS, "MyOwnCellTableStyleSheet.css" })
    TableStyle cellTableStyle();

}

Finally, when creating your cellTable, use the constructor that lets you specify which Resources to use

CellTable<Object> myCellTable = new CellTable<Object>(15, GWT.create(TableResources.class));

For a working example, look at the Expenses sample provided in the GWT SDK.