First I must tell you t hat the glass is not ordinary glass, The glass would be Armour Plate Glass and should be capable of putting up with quite a lot of abuse! That said, you would need to turn the table upside down and release the top from the legs. Then replace the top with whatever top you require, saving the top for replacement when the children are older. Another alternative would be to make a slip over cover of timber which you could remove as required. Or Teach the children NOT to bang things on the table????
You should be able to fit a piece of wood into the opening where the glass is.
You can get a piece of marble or other stone cut to fit the table top.
Take the glass piece to someone who can cut the wood or stone for the table to that exact size and just drop it in place
If you choose to put a piece of marble in the glass portion of the table top, do you realize the table will be very heavy and probably the legs will indent the pile of the rug. For that you'd need cups under the legs. It will be clunky to clean under.
If this were my table, I would cover the table top with something stiff, like a piece of 1/4" plywood or plexiglass covered over with fabric or a thick towel when the children are there. Or as Johnavallance said, "teach the children NOT to bang things on the table", very good advice.
A glass shop can make a piece of safety glass (like car windshield) if you still like the look of the glass. That is tougher than regular glass and won't cut you if it breaks. However, the wood or stone suggestions are good alternatives.
We had glass top coffee, end, and sofa tables for years with no damage.
Marble contact paper!
It might be a neat idea for a marble "look" laminate. That would be light and look nice, I would check to see if you can get a piece made to size at one of your local home improvement stores.
You can replace the glass with tile or wood. For wood, add a stencil or some type of painting that contrasts but compliments your general decor style.
as I look at your picture of this table, the bottom shelf would be really pretty where the glass is now- you could leave the bottom open or put in a large metal tray or some other item if you need it for storage
Epoxy would work, but it would be permanent. You can create almost any type of marble or granite, a solid color, or metallic finish.
Here is how to switch it to marble: https://www.youtube.com/watch?v=jiIOEcIPxmw
I have glass end tables and coffee table. It has lasted over 30 years. If you absolutely feel that you have to protect that beautiful glass from your children. Make a removable wooden top. Do not destroy that glass.
Take the glass out and paint the under side a faux marble.
I would determine the thickness of the glass and get darker boards to install in the middle.
Cut a piece of plywood to fit and cover with contact paper like marble or granite look.
Contact a counter top installer and see if they have any small pieces of marble left over from a job, They may be able to help. Also, look into using a marble tile as tile will be much thinner . That would fit or suit you table project better.
Unless you use the contact paper option, you're looking at a pricey upgrade. You need to remove that glass and then add the marble and secure it. It's much heavier and would probably require a professional to install it.
just cover that with piece of slab or train kids not to sit on it :)
You can likely pop the glass right out and then cover over the whole top or set something within the empty space. What you're suggesting is quite expensive, probably more than purchasing a new coffee table.