Question about Output of torchtext.data.iterator

I try to use torchtext library to help me handle a machine learning problem.

I use the simple data for an example, the goal is understand how to create the data object and dataloader before I start training model.

The csv file look like blow, there are only one column “text” and the element is sentence.

And I create a data object successfully.
2020-11-27 16-15-58 的螢幕擷圖

After I build the vocab, I can use iterator to show mini-batch like blow.
2020-11-27 16-17-46 的螢幕擷圖

I can understand the first column is index of words, but I cannot understand the second column, is it frequency of words?

The size column is talk about batch size, I understand it.