How to Handle Dynamic Tables in PDF Generation

If you are generating invoices, inventory lists, or financial reports, you are dealing with Tables. And in the world of PDF automation, tables are the boss fight.

Why? Because you never know how much data you will have. One invoice might have 3 items; the next might have 300.

Here is how to tame dynamic tables and ensure they look professional, no matter the data size.

1. The Page Break Problem

When a table grows longer than the page, it needs to break.

Bad: The table gets cut off mid-row, or the text is sliced in half.
Good: The table breaks cleanly between rows.
Best: The table breaks, and the Header Row repeats on the top of the next page so the user knows what the columns are.

Solution: Use a PDF generator that supports thead repetition. In CSS (for HTML-to-PDF), this is often handled automatically by the print engine if you structure your HTML with <thead> and <tbody>.

2. Column Width Strategies

Fixed Width: Good for “Price” or “Date” columns where the data length is predictable.
Percentage Width: “Description takes 50%, Qty takes 10%.” Good for responsiveness.
Auto Width: Dangerous. If a user enters a 500-character description without spaces, it might blow out the table and push content off the page. Always set word-wrap: break-word or overflow: hidden on your cells.

3. Zebra Striping

Reading a wide table is hard. The eye loses track of the row. Zebra Striping (alternating background colors for rows) improves readability significantly.

CSS: tr:nth-child(even) { background-color: #f2f2f2; }

4. Totals and Subtotals

If a table spans 3 pages, where do you put the total?

Grand Total: Usually goes at the very end.
Running Subtotal: Advanced financial reports often require a “Subtotal for this page” at the bottom of Page 1, and “Carried forward” at the top of Page 2. This requires a sophisticated generation engine that supports page-context logic.

5. Handling “Widows”

You don’t want a table header to appear at the bottom of Page 1, with all the data rows starting on Page 2. Use CSS page-break-after: avoid on your header elements to glue them to the first row of data.

Conclusion

Tables are the workhorses of business documents. Mastering their behavior—especially across page breaks—is the difference between a “glitchy computer printout” and a professional report.

Master the table. MergeCanvas has a powerful rendering engine designed specifically to handle complex, multi-page tables with repeating headers and smart page breaks.