But with Elecrtrum I can not import more than 30 addresses. When I add more than 30 keys those address won't display at address TAB
What version of Electrum are you trying to use?
I just imported this list of 40 private keys into Electrum v3.1.0:
("File -> New\Restore -> Import Bitcoin Addresses or Private Keys")
L3y7CSoyV7sPQzC3jKXjiMc391eXnnuZLf5SRdUmD1xCmz5eRF5V
L2KuYHa9hem7ra2Q48FqgiduvXnxmZCAUd5zVr7XeJc1woMkS9oi
L2A953BooZCcsuPRZNXBYdjzkmTjB4hDQmjejxTmQnLWsQU6GGeX
L3VYGYPAb49DRG5epyeZqWdh3vwyMNo6XtMGBFh5HTXs9cXnnX4j
KySmTV889te8v2fSy1dYhD9rcW5DVsrZ1tcrA9drd6uf1hdaTBUX
L5jCAL697W81UimR1xMen4ocbGs5XEhweyWKvsHqcEzStScA49C1
L2mfojT8bycfYupxEL1undKr4e3XVsNR4TGEvqUXoCTBMLB4PYDE
L3EmpvGDgayFqHsWQQ72w4Pqs6pCKfzyHw5ZP5qVZXCaqYCyfeLM
KzXFwdCAVpypA3LWaaxFSEgiNZoqi6iSzTsvy4fi6AYgWtMztUVv
Kx4jQd341Xf1gosKZgAtXwgQ6QqU4QsbDWtJoFBWZFHmNDfj5zW8
KzEixyyh8yGMV6AjFhogKCpcmuBCdUAoy35MsvGahs9SfmhUeoYJ
L4WHLLpPkvSoihsGbaZhYzFMgRxKbBEuAxgGvwgy2r33cnR6XCEX
L1NqoTWNtLZpiLo4KSRQc1wvZy9hGEwWrVX98iMqsXPRTQ3Nd6nw
L2mpb9DJDQiCknfvfCQTjyrMZ2vS8DTn4s1r8QYvVW2d5B67Y9PX
L14K4A5MzQbj2wkPwhYVk2kcM3EZQJPCrvuwTCTgBZCVLLRUQhzh
L4eg4SiTGr4bLFP9qBGd5U9TPF3But79cj7hTTBaktWJGHfJitoK
L5U43DHAjQiaraNpNvqq15SJoytDq9oe9PFdpYdbD4CCBFkH5bHv
Kz9HQcdHnEDw6LkDPwrYnEaer9evxubbrQFpxaX5Ak5GCBv5CDXR
L46B3B4DyKLn5B7K4Z4nqJsY7Vr8jpdSNGJSj7eJoms9YbwA69jf
L4PBsRVFGGF8tR22Ksgb5tocHZgACbXxcLS4XQkiYXD5UjL64xme
L12zBtBT6nADSxbw92uG2d5ub4yx1t6nTPVfy8n92USCCAcJtmbT
L46BVhYNYBpRkxLJiD6gmnKnpP1BcMVL4Zwtzb12JhAYVQtzRero
L47jHgyS4meyC8x4ub7b8e7Qdwek2GMRQm9UYxRmmtmK8Z41aJS1
L2yVbRNypK1kx5CzGZRcBbskUkHkXaLx3TiVz5SfnmdvijSaFSrQ
L4sJgGEUquQz2KFiCoMmNHQuFhcEbjx1SaLmzYtguByfi1tkwrPe
Kz7qhcQVpUeFWh6rPrVadsZMoNEmp9W8nujHTR9E45BXGsMncXoK
L2ccRMcWhxvRVy3ctqm5QRSSTmZAoQn6kavsKwQPHEaB54Vr778X
KxdMvDEbUhMcGuk15KZikzDQwsfoJygHR7T9rLzLeTqK5MHKq5hP
KxCYg3BzorXmzzaXtPHZFXBhgzzJxiy2sFDarDTjJVFfzB5WvgER
L5eVq8bSmFeWYzmcNvHWX9hcUmTTrkBDQYDF2VoVwarzdSFaJs12
KzfveAkG8WhDoxUnfrPFMskxXwTAjnVYNf45t6VESJ4RBikkKoEq
KzRPa9KtDgHNydKCLiE8P9tQZ3J3sj7M7o4Rh34GddHEcGouyx1B
L1zWrArHwo8KUPJaYZtJKktF2XnPjKgcWHezjeveu1BsP3hALoZd
KyLa6ujsCj1NXtXjg2n19CYmz2omaQgmT1cA5CvvivFUYUuu26vT
KyWY9L7avZJ8hE9uEXTh82oE6wjZw5q56ugcXE4Gmg6gaY36B8au
L4xqnQeY4znYLTyspRZmDF4J3d9TeYdSkhjZveRuHJjgycJaScji
L4epffCTTzT5zWo6wYyLFmbHneHzpT31isjPpodfcpHQMcqeqohT
L29YeYT1UKHbqN7Vdyrz6P7jHmvci1ECwaTrSv8xLALL3JCag5L4
L2CkCGGNewLz2Htk9Ni3FqXswTubY6SXcYPqAbgMZYeTcBiTMChb
KyXtRK6XcXs3nMkP9RDkLiajSMeRPntJMwY59kYKBBLUBMFhgXbo
It gave this:
The only time it won't show more than 30 (by default) is if you are using an HD wallet either created from seed or by importing an "xpub" or "xprv". In that instance, you simply need to use the following command on the console:
for x in range(0, 50): print(wallet.create_new_address(False))
That will generate 50 new addresses... you can change the "50" to whatever number you like.