Unfortunately, subreports within a table or matrix cannot be exported to Excel.  I am not sure why MS did not allow this with Reporting Services.  This came into play recently when I wanted to make a report that displayed detail data next to the header data.  This would be like displaying customer information and then orders and dollars next to the customer's information.  I wanted to display the data side by side with a running list of customer information on the left and a listing of orders on the right.  Unfortunately, lack of a vertical cell merge forced me into a subreport within a matrix.  This is not very efficient but worked.

The work around was to change out the table and go with a table of orders inside a list of customers.  Unfortunately, the table is easier when modifying 30 rows of data.  In a list, each field is a text box not a row and column.  Now imagine moving and resizing all of them at once, can someone say Crystal Reports :O(  Placing the table next to these text boxes also created interesting issues.  When there was multiple orders, the text boxes would slide down on the print preview leaving a gap in the customer information.  To remedy this, I had to place the table in a box.  I expanded the box to the bottom of the page. 

The last weird issue I had was how the table is treated in a list box.  I wanted to filter the table to only display that customer's orders.  Instead of calling my customer dataset for the list and order dataset for the table and filter orders based on customer; I had to make one dataset to return both customer and order information. I grouped the list by customer data, then I had to filter the table that was the same dataset by the customer number. 

In all, this was a very time consuming and annoying process just to display the data.  I am not sure why a table in a table does not work, why there is no vertical cell merge, and why subreports don't export to excel; but I encourage MS to fix these issues.