Not eating at the table - should I insist?

Encourage good habits now. Eating at the table together as a family at least once a day, should be a time for everyone to catch up with one another and socialise as a family - without the TV blaring out. As parents, we always insisted our kids sat at the table to eat with us - a habit they've continued it with their own children.

Yes you should insist they are at a table and you should be as well so that it is the norm. My children always sat at the table and ate with us

How long do you think you'll have an easy life if she does just as she chooses at this age? In my experience children prefer to know that someone is looking after them and that includes giving them boundaries until they are able to make their own.

If you/family are eating at the table the one year old will naturally want to be with you, a little encouragement will do the trick

Mindfulness of what we are doing, in this case eating, which uses our taste, sight, touch, smell, is not best appreciated whilst watching TV. Eating becomes secondary. Eventually I imagine we lose the ability to 'feel' what the food does for us.
Also the sharing aspect of a meal may be lost.

Switch the TV off. Put her in her high chair at the table with no discussion, just a statement that this is what we do at mealtimes, eat at the table. Who is the adult?

Table food
sofa no food

If that is what you want. I remember distinguishing between a meal with the family and a snack on the sofa.