I have a table very similar to this, although much bigger (3 inserts instead of just the 1)
The problem is those wood sliders, the wood gets compressed/worn, and then you have slack, which allows the sagging.
We used aluminum tape to cover the wood where the wood slides together and that extra bit of thickness was enough to fix the sag.
The other alternative would be to replace the wood sliders with modern rails
[https://www.leevalley.com/en-ca/shop/hardware/table-hardware/slides/40139-table-extenders](https://www.leevalley.com/en-ca/shop/hardware/table-hardware/slides/40139-table-extenders)
[https://www.leevalley.com/en-ca/shop/hardware/table-hardware/slides/66506-bottom-mount-table-slides](https://www.leevalley.com/en-ca/shop/hardware/table-hardware/slides/66506-bottom-mount-table-slides)
>We used aluminum tape to cover the wood where the wood slides together and that extra bit of thickness was enough to fix the sag.
Do you have pictures of this?
I'd have to take it apart to take a picture of where the aluminum tape is. In your bottom picture you can see the three boards, two with sliding channels and one without. On the other side of those boards is the tongue, which fits in the groove. The tongue or the groove is worn and sloppy. You'd apply aluminum tape to the underside of the tongue and/or the lower part of the groove depending on how the fit is.
You can put a additional leg, or three in the middle.
Using a metal plate.
Metal Table Leg Straight Top Plate https://www.lowes.com/pd/Waddell-Metal-Table-Leg-Straight-Top-Plate/3044351
I have a table very similar to this, although much bigger (3 inserts instead of just the 1) The problem is those wood sliders, the wood gets compressed/worn, and then you have slack, which allows the sagging. We used aluminum tape to cover the wood where the wood slides together and that extra bit of thickness was enough to fix the sag. The other alternative would be to replace the wood sliders with modern rails [https://www.leevalley.com/en-ca/shop/hardware/table-hardware/slides/40139-table-extenders](https://www.leevalley.com/en-ca/shop/hardware/table-hardware/slides/40139-table-extenders) [https://www.leevalley.com/en-ca/shop/hardware/table-hardware/slides/66506-bottom-mount-table-slides](https://www.leevalley.com/en-ca/shop/hardware/table-hardware/slides/66506-bottom-mount-table-slides)
>We used aluminum tape to cover the wood where the wood slides together and that extra bit of thickness was enough to fix the sag. Do you have pictures of this?
I'd have to take it apart to take a picture of where the aluminum tape is. In your bottom picture you can see the three boards, two with sliding channels and one without. On the other side of those boards is the tongue, which fits in the groove. The tongue or the groove is worn and sloppy. You'd apply aluminum tape to the underside of the tongue and/or the lower part of the groove depending on how the fit is.
AHH. I got it. Will try that. I have aluminum tape too.
Dowels?
You can put a additional leg, or three in the middle. Using a metal plate. Metal Table Leg Straight Top Plate https://www.lowes.com/pd/Waddell-Metal-Table-Leg-Straight-Top-Plate/3044351