I watch people in airports sitting and multi-tasking and eating.
'And' is a simple word we use all the time, to link subjects (Tom, Peter and Mary are all coming to dinner), objects (We'll serve duck breast, fish and vegetables), verbs (see example above), etc.
Be careful when linking verbs: the form has to be consistent, as in the above example where the '-ing' form has to be kept because it means people in the airports are sitting, multi-tasking and eating. If you say 'I watch people in airports sitting and multi-tasking and eat'. It'd mean something different: that the people in airports are sitting and multi-tasking and the writer watches them and eats.
Here are more examples: '...how to enjoy eating like the French and lose weight at the same time.', 'The key is savouring the tastes and smells of a good meal, eaten with family and friends, rather than wolfing down fast food...', '...pampering yourself with a well-prepared meal instead of polishing off a bag of chips...'.