Boys or girls or one of each? Because it does depend.
Boys - hours and hours ...and hours ...and hours of lining up toy cars on a toy road carpet rug (Argos have them) or playing with a wooden track railway.
Girls - hours and hours ...and hours... and hours of playing with dolls and doll houses. Dressing up, playing ‘house’, playing with (imaginary) horses.
Having living room picnics after they have helped you make the picnic.
All broken up with walks outside to count bugs, spot worms, birds or count buses, spot fire engines, count red cars.... play in the garden spoting birds, count bugs, spot worms......play in the sand pit, blow bubbles, chalk on the path, play with cars/dolls. Or inside weighing ingredients, mixing, making cakes, decorating cakes, doing finger painting, doing paper mache, painting paper mache
Some ideas here
www.goodtoknow.co.uk/family/children/75-ways-to-entertain-your-toddler-71744
entertaining kids is hard work.
I had my dc pre tablet era btw, DC didn’t have one until age 9 so had to be entertained constantly when very young. Now at teen age and no need for entertaining I actually miss being a part of the life of my offspring.