There's no way to have PD automatically do that, but your idea of a 2-second title is a great start. As long as there's nothing in the text box you also won't have to delete it afterwards, so start with a single 10-sec clip followed by a title and make sure you've deleted the title's text.
Next, select both the clip and the 2-sec title then copy them (
Ctrl+C is probably the easiest way to do that), then paste 9 more times so you have a block of 10 sets of clips. Now select all the clips and titles and paste that 10 more times and you'll have all the timeline placeholders arranged exactly as you want.
The final step is to drag each clip from the Media Room directly onto the desired placeholder on the timeline and choose the Replace option so that you have the correct clips for your project. The length of a 10 second placeholder will drop to 5 seconds if that's the duration of the replaced clip, but the reverse isn't true if the new clip is longer.
Unfortunately PD won't automatically shift the remaining clips left to fill the gap, so you'll need to right-click in the gap and choose Remove and Move All Clips on the Same Track to bring everything together each time you replace with a 5-sec clip.
An alternate approach would be to select all 100 clips in the Media Room and place them all on the timeline in one fell swoop (I'm assuming that they're already in the correct order). Next create a 2 second blank title and drag that to the end of the first clip, where you'll want to choose the Insert option.
Now copy that blank title and do the same thing by pasting a copy at the end of each clip. It's probably faster to use the keystrokes
Ctrl+ right arrow to skip to the end of the current clip, then
Ctrl+V to paste then choose Insert fromm the pop-up menu, then 2x
Ctrl+right arrows to skip to the endo of the next clip and repeat.
I know it sounds like a lot of work, but in reality you'll probably be done in less time than it took me to write all this up