Ok so I know a little about Margate, and a little knowledge can be a dangerous thing...
Margate, and the surrounding area, are home to the UK's biggest selection of micro-pubs, I think due to favourable local council licensing conditions.
As you arrive at the station, the beach and town centre are right in front of you, 5-10 mins walk. I would recommend heading past Dreamland and the arcades (and a grotty Wetherspoons) to the small but perfectly formed old town.
Here you will find a load of rather good small bars, with great beer and cracking views. The Little Swift, Fez, the Two Halves are all good in this area and just yards apart. The excellent Lifeboat is just in behind. If you carry on walking along the pier you'll reach the Harbour Arms with an awesome view back to town.
Only drawback is that the ground is back to the station and another 15 mins walk. But worth it to sample the delights of Margate. There's the Turner Gallery too if that's your thing (free entry).
There's one more micropub near near the station - Ales of the Unexpected - that doesn't open until 5pm, so an option for a pre train pint.