#Short Answer Instead of LEFT() use RIGHT().

#Explanation

The LEFT() function returns the leftmost characters, but the OP want to get the rightmost characters.

The following is a simplified version of the final formula, for explanatory purposes:

=RIGHT("Sector: Industrial Goods",16)

The following is the final formula; in order to improve readability, each parameter is inserted in a new line:

 =RIGHT(
   iferror(
     INDEX(
       IMPORTHTML(
         "http://www.thestreet.com/quote/GE/details/company-profile.html",
          "table",
          3
        ),
        8,
        1
     )
   ),
   16
 )

Short Answer

Instead of LEFT() use RIGHT().

Explanation

The LEFT() function returns the leftmost characters, but the OP want to get the rightmost characters.

The following is a simplified version of the final formula, for explanatory purposes:

=RIGHT("Sector: Industrial Goods",16)

The following is the final formula; in order to improve readability, each parameter is inserted in a new line:

 =RIGHT(
   iferror(
     INDEX(
       IMPORTHTML(
         "http://www.thestreet.com/quote/GE/details/company-profile.html",
          "table",
          3
        ),
        8,
        1
     )
   ),
   16
 )