statistics widow - all the texturs on landscape material are loaded in max dimension

hello guys i have problem if someone could help plz - this question related to optimization issue -
i did watch a lot off UT videos on ho creating landscape master material with blending layers - and they said - to not pain many (or more than 4) layers in same component off the landscape ----- now i did some tests and i found out that every texture i use in the material will be loaded in memory (u can see it from statistics * texture stats) — is that a bad thing ? because i have like 10 layers for the landscape - and all textures are loaded in full dimension (bc the player is close to landscape i guess) and the textures takes like 500mb of ram (is that the pc ram or gpu ram?)

sorry for longe post