A diaper changing table is helpful for some people because it raises the baby up to a comfortable height to change the babies diaper.
However you don't have to have a changing table to change a babies diaper and usually after the baby gets to 1 year old or older then you'll likely not be lifting the baby onto the changing table anyway.
I was given a changing table for my babies from my mother and I only used it for a few months and then found it easier to just change the baby on my bed with a changing pad.
I would keep a changing pad in my room in the living room and in the car.
When the baby and I were in the living room I would change the baby either on the couch or on the floor and if the baby and I were in the car I would change the babies diaper in the backseat on the changing pad.
or if we were in my bedroom I would put the changing pad on the mattress and change the babies diaper on the mattress.
You can just change a babies diaper anywhere that's available but just don't do it on a table where people are eating.
If in public try to take the baby to your car or in the bathroom out of courtesy.
The reason changing pads have straps is to secure the baby to the changing pad and changing table to prevent the baby or toddler from moving and falling off the changing table.
When you change your babies diaper using a changing pad on top of a dresser or something else high up then you should use the changing pad straps to secure the baby.
But if you watch the baby closely which you should anyway then the baby should not fall off and you may not need to use the straps.
Whenever you change a babies diaper on a changing pad or changing table then you need to keep a hand on the baby when you look away to grab a new diaper.
If you're changing the babies diaper on the changing pad on a bed or couch or floor then you don't need to the straps.