PM ITEMS,TASKS ACTIVITIES

Team,

I am new  to this and hence have a doubt.

when i use the tcode IW22 I can see some tabs  ITEMS,TASKS ACTIVITIES etc,,

there i can choose a  and entry from Code  group...Now i want to add some more entries under this code group...related to each tab... (ITEM,tasks,activities)   how can this be done...

If add some  entries to  a table will it be listed over there? please let me know ow this can be done

Thanks in advance mates.