Dance Floor with Tables on Either Side - Difficult to Mingle?

I'm so glad that I don't have to plan a wedding! So many choices and decisions ! No wonder it takes months and months ahead to plan!  From my viewpoint, who cares about this issue! Some will want to mingle, others to dance, others to eat and leave, or just sit at their tables. Now let's see....there's what to serve, what music,will it be loud enough or too loud? how to decorate, who will sit with whom,...what to wear, whether to have a gift registry, where to have the venue, what day of the week, whom to invite....how much things will cost, and whether one should simply elope or not, who not to offend, bridal shower or not, bachelorette party or not, what to serve, what to eat, (again!), the DRESS!, of course, how to handle the one relative who is a drunk, or the one who is obstreperous, the one who wants to make all YOUR decisions, my goodness, have you thought of getting married on a cruise ship by the captain? ...then, there's the honeymoon, whether to invite children or plus one's, or not....babysitters, what kind of cake, oh, don't forget the flowers! I'm going to take a nap after writing this.   

What is stopping you from making that hallway width passage-way a bit wider? I would absolutely create a wider pathway with a visual " barrier" of sorts.

Because, as is, some people may linger there and cause a crossing blockage.

Either that, or create passage ways on both ends of the dance floor for freedom of movement.

Yes if you seem to think so.

Now that I think about it, most weddings I've attended have been like this.  I don't recall problems trying to mingle, even if you couldn't march through the middle of the dance floor.  Why not just mention your concern to the venue and see what they say?  If they've been around awhile and have good reviews, it's safe to assume they know what they're doing.

It is pretty common to have tables on either side of the dance floor. I was a wedding DJ. 

As long as there is a open walkway to get around the dance floor you should be fine. 

Usually the head wedding party table is on the top with the dance floor right in front of it.  with guest tables on either side of the dance floor. On the other side of the dance floor opposite the head wedding tables should be open enough for foot traffic. That is the area, as a DJ, I would set up.

At venues I've been to before (where it's one room for everything), they've usually had the tables more spread out, then just moved / removed half of them to clear a dance space after the meal's completed

Almost every wedding I've been to has had a dance floor with tables around it. I don't know why you think that's a problem. People either cross the dance floor or they skirt around it. No big deal. 

you have 2 other choices....

and i doubt anyone will care or notice anyways.

How about a "meet in the middle" area with a few chairs and a small table. Add a few potted plants or other barricades and you've designated a pass way along one edge of the dance floor. 

Get guests mingling with a traditional seating plan. Traditionally hosts assumed that dinner guests were eager to socialize, to enjoy a meal with someone other than ones closest associates. And so naturally occurring groups like couples or families were ruthless separated. 

Groups of 8 people who weren't yet well acquainted were thus prompted to introduce themselves and get to know one another. Ideally, there will be introductions among all these new acquaintances after the meal. 

This relieves hosts of a great deal of making introductions and encouraging mingling. It is the mingling, the meeting new people that makes a party a good party, not the food, drink, or décor.