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Keep tables as simple as possible.
Do not use colour except lightest grey in the header row.
Make all . Solid margins / borders visible.
Format the table in ‘Layout’ > ‘Table properties’ > ‘Table’ tab, to make cell height 0.1cm and width 0.15cm. Layout > Table properties > Table tab. Make the left and right cell margins 0.15cm.
Note: make sure the Top field is set to 0 cm. Having any value in this field is a prime cause for lines in a table disappearing when you convert it to PDF.
To space the text and let it breathe, go to the Home tab, click the small arrow in the Paragraph group to open the Paragraph dialogue box. Se the spacing before and after to 2pt. This is enough to separate the text from cell borders and so make the table easier to read.
Highlight the header row and in ‘Layout’ > ‘Table properties’ > ‘Row’ tab, tick ‘Repeat as header row at the top of each page’.
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