any limits on javascript object or Uint8Array usage?

Are there any limits on javascript object usage?

i have an object which looks like

var chars = {
80: new Uint8Array([
0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xfe,0x00,0x00,
0x03,0xff,0xff,0xe0,0x00,0x00,0x02,
0xff,0xfe,0x00,0x00,0x00,0x0b,0xff,
0xe0,0x7f,0xff,0x40,0x7f,0xfe,0x07,
0xff,0xfe,0x02,0xff,0xe0,0x7f,0xff,
0xf4,0x1f,0xfe,0x07,0xff,0xff,0x81,
0xff,0xe0,0x7f,0xff,0xf8,0x1f,0xfe,
0x07,0xff,0xff,0x42,0xff,0xe0,0x7f,
0xff,0xe0,0x2f,0xfe,0x07,0xff,0xf4,
0x07,0xff,0xe0,0x00,0x00,0x01,0xff,
0xfe,0x00,0x00,0x00,0x7f,0xff,0xe0,
0x00,0x00,0x7f,0xff,0xfe,0x07,0xff,
0xff,0xff,0xff,0xe0,0x7f,0xff,0xff,
0xff,0xfe,0x07,0xff,0xff,0xff,0xff,
0xe0,0x7f,0xff,0xff,0xff,0xfe,0x07,
0xff,0xff,0xff,0xff,0xe0,0x7f,0xff,
0xff,0xff,0xfe,0x07,0xff,0xff,0xff,
0xff,0xe0,0x7f,0xff,0xff,0xff,0xfe,
0x07,0xff,0xff,0xff,0xff,0xe0,0x7f,
0xff,0xff,0xff
]),
// ... and so on, right now up to 23 attributes like the one above

i experienced some weird behaviour when i raise the sizes of the Uint8Arrays (like 50-100 elements more) --> out of memory

for the object above (including all 23 attributes) and some functions i get

{ "free": 4054, "usage": 1046, "total": 5100, "history": 2928,
  "stackEndAddress": 536959096, "flash_start": 134217728, "flash_binary_end": 375472, "flash_code_start": 134234112, "flash_length": 393216 }

and

>E.getSizeOf(chars);
=287

i am certainly not expecting a out of memory, even if the the charsobject would be double the size than before