Sub-table for history-based affine mode is described. In an exemplary aspect, a method for video processing includes deriving, deriving, for a conversion between a current block of video and a bitstream representation of the current block, an affine model for the current block based on affine related information, wherein the affine related information is stored in at least one first affine history motion vector prediction (HMVP) buffer of M first affine HMVP buffers or at least one affine sub-buffer of M affine sub-buffers (HB0, HB1, . . . HBM-1) into which a second affine HMVP buffer is divided, wherein the first affine HMVP buffer or affine HMVP sub-buffer being used to store affine related information of blocks coded prior the current block, M being an integer larger than 1; and performing the conversion by using the derived affine model.