If in your congregation, it is common for one person to receive multiple Yahrzeit reminder letters in the same period, you can now use the tabular format. In this format, the Yahrzeits appear in neat columns, in the middle of the page. In contrast, in the traditional format, the Yahrzeits were in-line with the rest of the text.
There is one thing you should be aware of, though. The tabular format is fixed–it has the name of the deceased, relationship to the living person, and Hebrew and Gregorian dates. There is no flexibility to include or exclude fields in that table.
With the Yahrzeit letters tabular format, you still do control the rest of the text of the letter–the areas above and below the table are free-form.