You could try any of the following:
Option #1: Image
When you resize the image/picture, though, it gets blurry/distorted.
- Use MS Paint to create an image of a right curly brace.
- Go to Insert > Picture. Select the image file you just created and then click Insert.
- Align the image with the cells in your data table.
- Right-click the image and go to Size and Properties.
- Select Move and Size with cells under the Properties tab.
Option #2: Using Excel's Right Brace Shape
This one, though, is a bit ugly.
- Go to Insert > Shapes
Select the right brace symbol.

Align the shape with the cells in your data table.
- Right-click the image and go to Size and Properties.
- Select Move and Size with cells under the Properties tab.
Option #3: Creating a Custom Shape
I created my own shape.
- Type
} into a cell, change the font to Times New Roman and set the size to 400.
- Click on Insert > Shapes > Freeform.
Using the giant curly brace as a guide, create points along its edges. Click each point and then, using the white handles, adjust the curves.

Copy your custom shape, change its colors and align it with the data table:

Right-click the shape and go to Size and Properties.
Select Move and Size with cells under the Properties tab.
Now when I try to adjust the height of Row 8, the shape automatically adjusts:

Here's a blank workbook that contains the custom shape: http://db.tt/XualR7K