Answered By: Jackie Stevens Last Updated: Mar 21, 2020 Views: 23
Guidance for formatting APA tables can be found on their website(s) linked below. Information for APA 7th style is very comprehensive, and APA 6th style is broadly the same (see the Whats New pdf linked below to understannd differences).
The APA rule for line spacing in a table is flexible: you can choose between single, one and a half, or double. It would likely depend on how much data is in the table and whether it is numerical or textual. The APA 6th guidance does say double-lined, but "specifications can be adjusted for clarity".