How to add a new row to a table?

I'm trying to create a dataset for my project. But I can't add a new line to my table. Second picture dataset. The first image is the error when I try to add the new line. Thank you for your help.

[dpb]

I've never run across whatever it is that created the tokenizedDocument class shown in the table, but however the symptoms variable was created for the existing table, the same process must be used for your new T variable table content.

ADDENDUM: I see it (tokenizedDocument) is in the Text Analytics Toolbox.

Use it on the input variables of the new table, T

T=table('yourheadersstring',tokenizedDocument('yourdocumentfile'),'variableNames',{'headers','symptoms'});
dataset=[dataset;T];

Salt to match your variables...