walk through space with slide retracted

Congratulations on your 179!
I concur. We keep our table strapped inverted on top of the cushion with the tie-down strap over the bar. That way, we can easily get through and open the door to the bathroom. The dinette ends on either side of the table provide a place to sit if we want to stop for lunch but don't want to set up the table. As was stated above, the only things not accessible with the slide retracted are the cabinet to the right of the sink and the storage area under the cushion next to the bed. I added storage space to the end next to the refrigerator (see my mods). That is also not accessible with the slide retracted. The two dinette ends could be if I were to add a door on the side or end of each of them instead of just having access through the top.

We often stop to picnic while traveling with our 179 and without opening the slide you have access to everything except the cabinet door to the right of the sink as you face the sink. 

It will depend on how you plan on carrying your table. If you strap in on top of the couch like some folks do,  you will have plenty of room to walk by and you will be able to open the bathroom door. If you strap the table next to the couch, you will not.