Equidox PDF Academy – Tagging Tables in PDFs

Tables are one of the most complex elements found in any document.  In PDFs, this is also true.  Properly tagging tables is required for assistive technology users to be able to understand the relationship between the rows, columns, and cells.  Interpreting table data without proper tagging is nearly impossible, as the content will be presented as a stream of numbers and words with no indicating of how they fit together. 

Row and Column Headers are a Must

Row and column headings, particularly if there are more than one in a given table, must be identified so that it can be understood what the cell data represents. They must be tagged as table headings, and any spanned cells (merged cells) must be identified in the table summary.

Include a table summary

Table summaries provide the reader with information about how the table is organized.  Spanned (merged) rows or columns and multiple headings within the table should be pointed out, as well as any blank cells or other oddities. This information provides the assistive technology user a framework of how the data is organized so they can better make use of it. 

Beware the blanks

Blank spaces in a table can be confusing.  Some screen readers do not interact with them accurately, and some users can misunderstand how the table is created, or assume the table is faulty if they hear “blank” “blank” “blank” too many times when reading through the table.  Correct this by inserting “intentionally blank” or “no data” in the cell, and should be mentioned in the table summary.  Example: “Table with blank cells in rows 3, 4, and 5.”

The table summary for the table below would read:  “Table with two header rows, merged cells in rows 1, and blank cells in column 3 and 5.”

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Equidox’s table editor uses AI

If you are using Equidox to remediate PDFs, the Equidox Table Editor uses artificial intelligence, specifically computer vision, to detect table elements.  Equidox also provides a table preview from the table editor so you can check your work. Tagging tables can be done in a fraction of the time it takes with Adobe Acrobat.   

Tammy Albee

Tammy Albee | Director of Marketing | Equidox Tammy joined Equidox after four years of experience working at the National Federation of the Blind. She firmly maintains that accessibility is about reaching everyone, regardless of ability, and boosting your market share in the process. "Nobody should be barred from accessing information. It's what drives our modern society."