I can't figure out how to sort specific columns in a table

You should be able to sort a table.  How many columns?   Is there just one author column?  If just one column for the author, how is it laid out? Is there a header row?

Firstname Lastname  or Lastname, Firstname.   If it is the former, are there any suffices on the Last name like Jr, III, esq.? 

All this matters.

Usually i put in the column headers and for a test i did author, title, date.  If you have Authors are you putting it Lastname, FirstName ?  or Firstname Lastname ?  That does get a little tricky but i usually put the last / first names in separate columns otherwise the Lastname, Firstname is a better choice.  You should be able to select the entire column and the Sort button will appear   allowing you to go ahead and sort based on your data.

You haven't responded.  Maybe you have it working.  In anycase. put your cursor in some table cell.  Doesn't seem to matter which in my testing.  Click Tools > Sort.   In the "Sort by" dialog that opens, "First cell in a table row" is defaulted.  Click Edit or  New as desired.   Give the sort a new name if it is something you will reuse. In the next dialog, put the number of the Column in the column box.  If the author's names are in column 2, put in 2.  Leave Line at 1 (unless you have multiple lines in each row.)   If your column with Author Names is in the form 'last name, first name'  put (leave) 1 in the Word box.  If it is the form of 'first name last name' put -1 in the word box.  This will sort on the last word in the cell.

If there are suffices to some of the names as I ask in my original response, this will get tricky if in the form first name last name.