Want help to filter merge cell in Microsoft Excel

I am using Excel 2003. I want to be able to filter merged cells (that are in one column, covering several rows) so that all the data associated with the merged cell appears and not just the top line. e.g. set up a table with two columns and an auto filter at the top. In the left column put certain categories of data, for example say food types e.g. fruit or meat, and then in the right column the actual food, so for fruit you could have apples, bananas and pears. Now for presentation purposes I want to have the left column merged so that the food category appears once vertically centered in the middle of the rows, but I want to be able to filter this column to pick up all the data i.e. if I filter for fruit I want to get apples, bananas and pears not just apples.

You could try grouping your data. First, go to Data/Group and Outline/Setting and uncheck Summary rows below detail and Summary columns to right of detail. Let's say for example your data looks like
A B
1 Apple
2 Fruit Oranges
3 Pears
Select rows 2 and 3. Then click Data/Group and Outline/Group (do this for all of your groups). When you filter for Fruit, you will initially see Fruit in Col A and Apple in Col B, but you can expand the group (by clicking the + sign on the left side of the screen) and should see the rest of the group. Not a one step solution, but the only other thing I can think of is to put a helper column to the right of your data (Column C) and enter "Fruit" in C1:C3 and change the font to white (so it does not appear on screen or print) and filter on this column.

I will recommend you to read under F1 in excel about filter cell process in detail. In that you can find a number of references.