Windows 10 Edition is insanely lagging

Windows 10 Edition is insanely lagging, one time I was playing on it with my brother who was on his iPad and We made a bridge over lava in the Nether and my game lagged for like 10 minuets and I tried to move around but if failed then when it unfroze I fell into lava plz fix this (I do understand it's in beta)

Fan, Dylan
Mojang is the best game company and I've been playing Minecraft for about 3 Yrs now and I know a lot about the game, like that the game's name was changed 3 times from CaveGame to Minecraft: Order of the Stone, then finally Minecraft and the Iron Sword, Apple, Old Leather Amor, Old Cobblestone & and Even old grass block

Please keep the description focused on the bug. Thanks.

-kaleb418