A family of Microsoft word processing software products for creating web, email, and print documents.
Instead of the "template" from Avery (actually, a document, not a Word template at all), use Word's built-in label definition for the 5302 cards.
Start by opening a new blank document. Click the Start Mail Merge button and choose Labels in the menu. The Label Options dialog opens. Select "Avery US Letter" in the Label vendors dropdown if it isn't already there. Then scroll to the 5302 Small Tent Cards item in the Product number list. Hint: The numbers are sorted "alphabetically" rather than "numerically", so all the numbers that start with 0 through 4 come before any that start with 5, regardless of how many digits they have.
After that, you can choose the data source, enter the merge fields, and finish the merge. You may want to print a single page on plain paper first, and hold it up to a light with a label sheet behind it, to see how the alignment turns out.