Is this the only eating space ? How big does it need to be when expanded and how big is the space .From the pics it seems you have not a huge space for expansion so I need a to scale plan I think all the furniture in the bumpout seems to be too much. But I need mor einfo for sure. As for finishes on tables so much depends on the wood and hoestly nothing really stands up to neglect.. Maybe a table cloth for the teens to use for what is needed . My kids did homework at the island not on my good DR table. If the expanded table can fit there I would choose a nice marble top or granite and just have it the expanded size all the time or really even glass both easy to wipe off from spills . So post a bit mor einfo here in comments DO NOT start another post . Pics of the plan posted in jpeg format and any answers all here .

Patricia is right, a top made of a solid surfacing material like what is used on counters would be best. I like Ballard Designs' stuff, but I doubt their tables would hold up to the treatment you're describing. You could put a glass top on it. If you really want wood, look to see if there is a Canadel retailer near you. I have had one of their tables in my kitchen for 20 years and it has a very hardy surface. But I don't know if any wood surface can stand up to teenagers. :-) We are pretty good about using placemats and trivets. If you find a Canadel retailer, ask them about it. Other users of this forum have had good things to say about Canadel as well. The other advantage to them is that they have many styles, colors and sizes. Everything is custom built after you choose the combination you want.

https://www.birchlane.com/filters/furniture/sb2/extendable-round-dining-tables-c1805508-a1278~2251-a149112~514599.html

Not expandable but have you thought about a large square? Often they are bar height which with teens would be fine (not the best with younger kids) I was at a meeting the other night at a large sq. One person was at a side but there was room for two if needed. Would give a similar feel

Perhaps look at rectangular table that’s expandable, and use padded tablecloth until they’re old enough to use properly.

@BeveryFLADziner thanks ! These look like good options and I hadn’t looked at BirchLane Thank you so much !!!
. @Patricia Colwell Consulting there is actually quite a large space plenty of room when I measured for 60” plus another 5ft for chairs. I will have to get exact space measurements again . Currently not home . We are new In the house . Light fixtures and decor are works in process for now I’d just like to decide on a table and want something I don’t have to worry about it . (Furniture in bump out is where it landed off the truck so nothing set in.stone . We do use a marrimekko coated cotton table cloth but I like the look of wood and don’t want to worry about always having it covered -function is the key but obviously would like it to look nice . Kids do do homework at the island and their desks but someone always end up spreading out to table with a drink and don’t want to worry about them using a coaster. seems like all the “nice tables “ I’ve looked at aren’t practical for my family since I know for as much as I try someone will forget to use the coaster -they often push the tablecloth off for writing .etc Our old house had a built in banquet . We are a family of 6 with as mentioned four teens so while some are away at college I like the idea of expanding so as they bring partners/ friends etc there’s room for everyone. Why I feel a 54” would be ideal for everyday .
When the kids were little we had a farmhouse style table from pier one I think??? Nothing too fancy or expensive but it held up great! I didn’t have to worry about a thing . We got rid of it years ago due to a move . Have no idea what it was made of ??? But lookint for something like that - wondering if mango wood leaves water stains ???
@kandrewspa Funny you mention Canadel - that’s what I bought for our dining room table just over two years ago. Very solid and loved that I got to pick out base color shape etc but you still have to be very careful with glasses etc more so than I’d like to have to worry about for everyday use. We only use our dining room table for holidays . I had bought the extra care treatment when I purchased my table and was assured they’d come out and fix any little scratch or water mark sales lady told me she had had them out twice already and both times made her table good as new no questions asked ! Last year after thanksgiving dinner I noticed very light scratches across the table - not very visible or severe I’m guessing dishes were pushed across the table rather than being picked up . I emailed asking them to come repair and suddenly my extra protection that I was guaranteed would cover anything -didn’t cover the marks !!! so very disappointed in my customer care after spending money on the table and buying into the whole idea of the extra protection covering anything !!! The dining room table is rectangle which is why I like round - just really like being able to see everyone’s face :-)

Thank you ! I hadn’t seen anything like these - fun and different !

It sounds like you want a table that can seat 10 people. Have you considered the expand table? It can be as small as a console or even a coffee table and become as big a table as you need (seats 12) I particularly like the companion cube which holds 5 stools in a little ottoman. There are also a number of different finishes. Watching all of their videos just kind of blows my mind.

https://expandfurniture.com/product/junior-giant-table/

here’s one i found. If you look for laminate top tables.. you might have to hint around a bit.. that may work for you.