Merge tables from different sources (APA citation) What I want to do is copy a table found in paper 1 and expand upon it using information from different sources. I'm doing a literature review and the table I found gives a nice summary of  the literature, however I need to expand it since it is missing a few notable contributions. I want to maintain the format of the original table and merely add a few rows to it.

Making the table is not the problem, I'm just completely oblivious as to how I should properly attribute the original author of it in APA style + attributing the additions.
If a student of mine asked me this I would say to write a brief introduction sentence (or paragraph) just before the table and indicate (verbally, as some say) as follows:


  The following table is based on work from Smith (2012) but does
  include additional rows. Those additional rows are marked with an asterisk (*).


Then I would simple mark the new rows with an asterisk.

The point is to make it very clear what originated with you and what originated with someone else. This does that clearly.