For most of what I read a TOC is a nice but not required feature. If it is something like Harry's massive Sherlock Holmes Omnibus then it is critical. For my recent post of the first Zorro book it is not needed. If you are posting single books it is a lot like distance signs on a road, it just allows you to know where you are along the path (and the page count at the bottom of the screen also does that.)
For me, please post them. I am sure that the cover art will more than make up for any (very) minor problem that a lack of a TOC may cause.