Wrapping Text in Merged Cells

I have a form in Excel that contains a field for users to enter a description. It covers 4 columns and 11 rows and is merged into one field. If users enter 2 rows of text or less, it will wrap perfectly. When they enter the third row of text, all it shows is "#########..." on a single row.

I've seen in this Forum that I need to avoid merged cells if at all possible, and that if I can use a text box then I need to do that instead. However, I am not sure how to use the text box and make it transparent to the user that they are entering their data into a text box. I need them to be able to tab to the text box in the appropriate sequence and on to the next field as the form dictates.

Whatever solution I implement, merged field or text box, it must be able to handle more than 255 characters.

Any and all assistance is greatly appreciated.