Use your own entries
Each nonblank line is one square. Duplicate entries are removed. Choose the card size, use an optional free center on odd-sized cards, then print using your browser at its normal scale. Each entry must fit in its square; shorten long entries before printing. To make a caller list from the same entries, shuffle that list.
A worked example
A 5 by 5 card with a free center needs 24 distinct entries. Without a free center, it needs 25.
Before you use the result
This makes one card at a time. Browser Print can save a PDF if your system provides that destination. The site does not promise that separate cards will be unique.