Each field, or column, in an attribute table has properties that describe its contents and how the data in it should be displayed. Set the field visibility on columns in a table to save space by hiding those you don't readily need. Once you hide a column in a table, it's no longer visible on other dialog boxes, such as the Pop-up window when you identify a feature, and the Attributes pane for the selected features you want to edit.
Press the Ctrl key while double-clicking the field name of the column header to hide a single field. You can also turn off field visibility by right-clicking the column header and clicking Hide Field 
. Optionally press Shift while selecting multiple fields to hide multiple columns at once. If you open the field's view for the layer, you can confirm that the field visibility is unchecked.
To show all fields again without opening the field's view, click the menu button 
at the top of the Attribute table and click Show All Fields. Any hidden fields become visible in the attribute table and on other dialog boxes.