Table of Contents是目录的意思。
我想期刊应该是要你写一个Table of Contents graphic ?
The Table of Contents graphic should capture the reader's attention and, in conjunction with the manuscript title, should give the reader a quick visual impression of the essence of the paper without providing specific results.

个人理解，这是要求用一个表格来显示文章的主要结构和研究内容，也就是相当于一本书的目录的作用。