one way to do what you want.
Select all of your columns of data (Table) and sort it based on your choice of column(s). This should regroup all your remaining data together. (leaving the blank lines at the bottom.)
Next Insert a column at a location of your choosing (ie. to the left of everything - column A). In the top cell (ie. A2) enter 1.
In the cell directly below it (ie. A3) enter the formula =A2+1.
Now select and copy that formula (cell A3) and paste it into all the cells in that column, all the way down to the last row of data.
If done correctly you should now have a numbered list of your remaining vendors and sorted just how you want them.