I don't think you will keep squirrels off a free-standing bird table. They even manage to run vertically across my pebble-dashed walls, they'll get anywhere.
I have a hanging nut feeder which attracts the usuals, plus the occasional treat of green and lesser spotted woodpeckers.
For the other birds, I feed them with fruit-flavoured pellets which I spread over a tray and put immediately outside the conservatory door on an eye-level table. This way you keep an eye out and at the approach of a squirrel (or hated magpies) you can bring it indoors. Also you can bring it inside when you go out.
It is a bit labour-intensive but suits me, and the birds are used to it. As soon as they seem me appear downstairs in the morning they land outside waiting. The robins have even perched on my bedroom windowsill to remind me to get up !!!
P.S. Chilli powder will effectively deter foxes from digging up your bedding plants.