Listen, nobody can play with their baby all the time, nor should they! I think that leaving them be is an important part of their development. DD would tear apart her book basket, she'd just sit with toys and babble to herself. I was never far. Sure, I'd sit and talk, play, read, giggle, stack, chase.......but if I needed to shower or unload the dishwasher or make a call, she was happy on her own. Be sure she has lots of things to do that are at her level, and check in with her so she doesn't feel "left". My dd could see me, the way our house was set up, so that helped.
At 5 months, he is still very little, but my dd liked her excersaucer at that time. I'd say she was fine for 20 minutes or so, but that was enough for me to get things done here and there!