It's annoying, I know (I can't even properly review First Posts on Web Applications right now), but increasing the limit will only cause a larger backlog, less enthusiastic/attentive reviewers and hence worse reviews. Based of what I've seen I'm sure your edits are correct, but there are a lot of suggested edits across the network which do need proper scrutiny. Therefore, the number is quite low (40 on most sites, with a couple exceptions).
Since you're having this problem too, I've posted a plea for help on Web Applications Meta: Please help reviewing suggested edits! </shameless plug>
I now realize that you do have enough reputation on Web Applications to review regular suggested edits, but was annoyed because you needed empty review slots for suggesting edits to tag wikis/excerpts. In that case, the solution to your problem is ... so obvious I'm not even going to mention it.