Sorting is an efficient means of organizing your data in alphabetical or sequential order, helping you to better understand the data you're working with. You can discover the largest and smallest values or perhaps the most and least significant features in a layer. When sorting a column's values in ascending order, the values are ordered from A to Z or from 1 to 10. In descending order, a column's values are arranged from Z to A or from 10 to 1.
You can interactively sort in the table window or by using a table sorting dialog box, which makes it easier to sort more than one column.
Note:
Sorting applied to a table is not persisted after closing if the table was opened from the Catalog pane or from a catalog view.
If you want a table that is permanently sorted, use the Sort geoprocessing tool.
Basic sorting
To sort a table based on a field, double-click the field name. The first sort is in ascending order. Each subsequent double-click switches the sort order.
Alternatively, right-click the field name on which to sort and choose Sort Ascending 
or Sort Descending 
to immediately sort the table.
Press the Shift key while double-clicking multiple columns to sort by multiple fields.
Custom sorting
Right-click a field name and click Custom Sort 
to open the Custom Sort dialog box to sort based on multiple fields, clear the current sort order on the table, or make a case-sensitive sort. Optionally, use the keyboard shortcut Ctrl+Shift+S to open this dialog box.
Remove sorting
Remove or undo the sort order by pressing Ctrl+Shift+U in the active table. Alternatively, click the Clear sort button at the bottom of the table view.