Stop paying twice for the same guest
A platform earns its cut on somebody who had never heard of you. On the ones who already know your name, it is a toll.
A real Clay site, built from a Google listing
Forty covers a week through the platform, at an average bill of €35, is €1,400 of dinner a week that came to you with somebody else's name on it. At fifteen per cent the invoice takes €210 of that, which is €10,920 over a year, on tables in a dining room you already fill.
Some of that is money well spent. A visitor in town for three days who had never heard of you booked a table, the platform earned its cut, and there is no argument to have. The rest are people who typed your name into Google and booked through whatever came up first. That is the half worth taking back.
A listing earns its fee once
A platform is a shop window on a street you do not live on. It puts you in front of somebody who was never going to find you, and fifteen per cent of that table is an introduction fee. Paid once, for a customer you did not have, it is fair.
Your own site cannot do that and should not pretend to. It sits there and waits for a name to be typed. Which of last month's bookings were strangers and which were regulars going through the platform because it came up first is a question only your own invoice can answer.

A time, a table, a day
One engine, three shapes. A service is a length of time at a price. A table is a capacity and a count, so a party of four is offered every time any four-top is free, and nobody is shown a seating plan. A rental is a first day and a last day, priced as they pick.
What it will not do is touch a card. A deposit is stated, worked out on the server, printed in the guest's confirmation and in yours, and paid when they walk in. If you need the money held in advance, this is not that, and it can only be set on a table in the first place.

What moves onto your own page
What you get

Three shapes, one engine
A time in the diary, a table for a party, or something hired by the day, one control switches between them, not three products.

The guest is yours
Every booking emails you the guest's name, phone and note, and pressing Reply reaches them rather than a support desk.

Found by the name they typed
The site is built from your Google listing, photos, hours, rating, map, so the page they land on is already about you.

€29 a month, flat
Pro is €29 a month or €290 a year, ex VAT, whatever the page takes. There is no fee per booking on any plan.
What it looks like when it is live
Drawn rather than described, the page, the address, and what it can switch on.
Questions
So should I leave the platform?
No. It brings you people who had never heard of you and your own site never will, so keep the listing. Take the ones who searched your name on your own page instead, table booking is the same engine, without the cut.
Is there a fee per booking?
None, on any plan. Booking itself sits on Pro, €29 a month or €290 a year, ex VAT, and a claimed free site draws the page but the server refuses the booking. So the sum is a flat price against last month's commission line, not a rate per cover.
Can I take a deposit so people turn up?
It is stated, not taken. The amount is worked out on the server, named in both confirmation emails and paid when the party arrives; no card is touched anywhere in the booking. It can also only be set on a table, from a party size you choose upward.
Can a guest move their booking?
No. They can cancel it themselves up to the notice you set, and moving a table is still a phone call. They also have to make an account with an email and a password to book at all, there is no guest checkout: how appointments work.
Should I come off the platform entirely?
Usually not. It brings people who have never heard of you, and your own site does not do that. The argument is about the second visit: somebody who has already been should be booking on your page, not through a listing that charges you again for a customer you earned.
Real sites, made with Clay
Open one. It is the live site in a frame, not a screenshot, so what you see is what it looks like right now.
Do the sum on your own invoice
Search your business, look at the page it makes, and hold a flat monthly price against last month's commission line.