This is not an easy project, and once you start, you will be committed.
If you are willing to commit, then you are correct you will need to remove the tile and grout.
If you are lucky and can get a putty knife under the tiles, some will pop out. Many will break.
Consider getting a Fein Multi-Master or its equivalent. The oscillating blade will make short work of the tile, perhaps even the grout.
If you do not have a Multi-Master or equivalent, then removing the tiles may need breaking with a hammer so easier to remove smaller pieces. The grout will either need to be removed with chisel, or angle grinder. Note the latter will make a LOT of dust, but it will go fast.
Once all the tile and grout has been removed you will then have a large but shallow cavity. It will likely be uneven. If this happens, you can consider pouring in floor levelling compound. This is a cement like material mixed with water which self levels. Just ensure you make the table level FIRST.
. This could also allow you to get the cavity to match whatever material will be used to replace the tile.
Once the cavity is level you can either attempt to fill with a single piece of e.g., plywood. If so consider cabinet grade. This will be thin (approx 1/4in) and you need this to have any voids patched. The normal big box store plywood will have voids.
An alternate is to consider the wood looking laminated flooring. You could get a contrasting wood/colour so you may be able to avoid painting the table.
Either way you need to glue down the material. Liquid nails should work. Just place some weights on the table to try and get this to be a flat as possible.