In short, no, it's not okay.
Remember to never read your slides to your audience. For starters, the audience can read a slide much faster than you can read it aloud. And more importantly, you want the audience to pay attention to the words you speak, which should be far more interesting, eloquent, delicious, thoughtful, and red-hot! than what you place on any slide. Each slide should contain just enough information to highlight the major points and support what you say.
I recall a workshop I once attended where the facilitator stood at the front of the room and read material verbatim from the handout she had provided. I wanted to scream. I walked away having learned nothing I could not have read on my own.
When a presenter looks up at the projection screen to reference the material or to read it to the audience as opposed to looking at his/her laptop or computer, it's akin to ...
"What if my audience is immediately bored?"
"I"m so scared. It's possible no one will really want to listen to me, right?!"
"What do I do if everyone checks out on me?"
Is it okay to throw in an activity or make a couple of jokes on the fly to keep everyone engaged?"
"How do I keep everyone from losing interest?"
"What should I do to 'wake up' my audience?"
If you have questions similar to these, you are not alone. The best advice I can give everyone is to plan your presentation so there is no opportunity for the audience to get bored. Be proactive so you are not having to pull something out of the air to wake up your audience and, most importantly, so your audience doesn't need waking up in the first place. I know. I know. *slowly shaking head with eyes closed in affirmation to nonverbally say "I feel you"* This, you may think, is easier said than done. Not really. Trust me.
I will share with you the structure I use, and it never fails. Never. And this structure, this pattern is now yours. Use it, and I firmly believe you will keep your audiences interested.