A traditional Lookup table only allow you to retrieve data in a left to right, top to bottom frame of reference. You search for matching data in the first column and return values in the range of cells directly to the right. With the combination of the two Excel functions Index and Match you can look to the left or the right of your search data.
Lookup tables also restrict you to searching the cells defined by the range of cells selected to make up the lookup table which means your data sets have to be grouped together. Any data added outside of that range cannot be seen. The Index / Match combination will allow you to select an entire column or just a range of cells that you select within that column.
Syntax:
=Index(DataYouWant,match(LookForThis,DataToSearch,0))
This will match up columns DataYouWant and DataToSearch beginning with the first cell of each defined column, find the LookForThis value in the DataToSearch column and return the value in the corresponding row of the DataYouWant Column.
Columns or defined ranges can be seperated by multiple columns and they can be on seperate rows as well. If the LookForThis data is found in rows 6 of the DataToSearch then the value in row 6 of the DataYouWant will be returned - even if the data sets are seperated by multiple rows of other data.