I can see how to do this manually, and it shouldn't take too long.
Insert a new column A, then click on B1 (Fruit) and click <copy and
paste into A2 to A-whatever, where "whatever" is the number of cells
occupied in column B.

Then click on C2, hold down <shift, press <End once followed by
<down-arrow then release <shift (this will have highlighted all the
contiguous data in column C), then click <copy, move cursor to bottom
of column B data and paste the desserts directly under the fruits. Then
copy the word Dessert from C1 to Awhatever+1 down to as many items as
there are now in column B.

You can do a similar thing for the Drinks which are now in column D,
i.e. copy the the data to the bottom of column B then copy the word
Drinks into column A as required. You can then delete columns C and D.
This should only take a few minutes at most.

Hope this helps.

Pete