For each trace in the trend, you can configure it to show the description. There isn't an option to show both the tag name and the description.
could you guide how that is done and does it need to be done for each trend.
psg912 if you right click the trend and then select Configure Trend, you can change the legend under Trace Options > Legend Label. The instructions are in the User Guide section Configure trend options and style following Step 1 and then 5b. It does have to be done for each trace.
Hi lposner ,
Thanks for your guidance, actually I wanted the text below the trend to be modified , see the attached pic , hopefully that will explain the issue better. 
Looking forward to your response.
Regards,
Hi psg912 if I understand correctly, you are trying to create a custom legend on an adhoc trend table, which is not possible. For the main display, you can edit the legend label by selecting the <Custom> option, but I am guessing that you specifically want to do this on the adhoc table instead?