People from some countries have to fill out a travel form; most don't. Everyone does have to list what they were doing for the last 10 years. By 'activities' they mean you should list the main activity for each time period. Do not leave any gaps in the timeline. So for example you state that you were studying at the University of _____ from June, 2003 to May, 2005; you were unemployed from June, 2005 to August, 2005; you were working at the X Company from September 2005 to the present. If you are not one of the people who has to list all travels, then you do not have to mention things like your yearly two-week trips to wherever during your employment.
If you were just at home doing nothing for some of the time period they want info about, do not be tempted to just leave that out. The visa officer will then resend you the form and ask you to fill it out completely, thus delaying the processing of your visa. Just say you were unemployed. If you were a housewife or househusband, that is fine - just mention it.
