If I understand correctly, a transition isn't really what you need. I presume you'll have the video of the speaker on a lower track, let's say V1, and the slides on say V2--at least not for the purpose of moving the slides into the frame. Assuming each slide is a separate assets (as opposed to a video clip), you'll probably want to use the Motion controls on the Effect Controls panel, specifically Position & Scale, to get them set in the right position--basically, a picture-in-picture arrangement.
As far as bringing each of the slides into view, you have at least a couple of options:
- add a transition at each end or, if the slides are all lined up without gaps, then transitions between them.
- keyframe the Position at the head to move the slide on from the right and off to the left.
Note that once you've can set up one slide, you can save a preset and then apply it to all the others in a snap.
To learn more, consult this page in the help: Adobe Premiere Pro Help | Motion: position, scale, and rotate clips. It has links to a couple of video tutorials.